Really interested to see that others have been receiving this too, we have been having this flagged on a couple of sites / accounts over the past month or two
Basically, Google Data Studio's schema error view is 'richer' than that of Google's schema tool (stand-alone) which has been left behind a bit in terms of changing standards. Quite often you can put the pages highlighted by GSC (Google Search Console) into Google's schema tool, and they will show as having warnings only (no errors) yet GSC says there are errors (very confusing for a lot of people)
Let's look at an example:
... basically the schema tool separates issues into two categories, errors and warnings
But Google Search Console's view of schema errors, is now richer and more advanced than that (so adhere to GSC specs, not schema tool specs - if they ever contradict each other!)
What GSC is basically saying is this:
"Offers, review and aggregateRating are recommended only and usually cause a warning rather than an error if omitted. However, now we are taking a more complex view. If any one of these fields / properties is omitted, that's okay but one of the three MUST now be present - or it will change from an warning to an error. SO to be clear, if one or two of these is missing, it's not a big deal - but if all three are missing, to us at Google - the product no longer constitutes as a valid product"
So what are the implications of having schema which generates erroneous, invalid products in Google's eyes?
This was the key statement I found from Google:
Google have this document on the Merchant Center (all about Google Shopping paid activity): https://support.google.com/merchants/answer/6069143?hl=en-GB
They say: "Valid structured markup allows us to read your product data and enable two features: (1) Automatic item updates: Automatic item updates reduce the risk of account suspension and temporary item disapproval due to price and availability mismatches. (2) Google Sheets Merchant Center add-on: The Merchant Center add-on in Google Sheets can crawl your website and uses structured data to populate and update many attributes in your feed. Learn more about using Google sheets to submit your product data. Prevent temporary disapprovals due to mismatched price and availability information with automatic item updates. This tool allows Merchant Center to update your items based on the structured data on your website instead of using feed-based product data that may be out of date."
So basically, without 'valid' schema mark-up, your Google Shopping (paid results) are much more likely to get rejected at a higher frequency, as Google's organic crawler passes data to Google Shopping through schema (and assumedly, they will only do this if the schema is marked as non-erroneous). Since you don't (well, you haven't said anything about this) use Google Shopping (PLA - Product Listing Ads), this 'primary risk' is mostly mitigated
It's likely that without valid product schema, your products will not appear as 'product' results within Google's normal, organic results. As you know, occasionally product results make it into Google's normal results. I'm not sure if this can be achieved without paying Google for a PLA (Product Listings Ad) for the hypothetical product in question. If webmasters can occasionally achieve proper product listings in Google's SERPs without PLA, e.g like this:
https://d.pr/i/XmXq6b.png (screenshot)
... then be assured that, if your products have schema errors - you're much less likely to get them listed in such a way for for free. In the screenshot I just gave, they are clearly labelled as sponsored (meaning that they were paid for). As such, not sure how much of an issue this would be
For product URLs which rank in Google's SERPs which do not render 'as' products:
https://d.pr/i/aW0sfD.png (screenshot)
... I don't think that such results would be impacted 'as' highly. You'll see that even with the plain-text / link results, sometimes you get schema embedded like those aggregate product review ratings. Obviously if the schema had errors, the richness of the SERP may be impacted (the little stars might disappear or something)
Personally I think that this is going to be a tough one that we're all going to have to come together and solve collectively. Google are basically saying, if a product has no individual review they can read, or no aggregate star rating from a collection of reviews, or it's not on offer (a product must have at least one of these three things) - then to Google it doesn't count as a product any more. That's how it is now, there's no arguing or getting away from it (though personally I think it's pretty steep, they may even back-track on this one at some point due to it being relatively infeasible for most companies to adopt for all their thousands of products)
You could take the line of re-assigning all your products as services, but IMO that's a very bad idea. I think Google will cotton on to such 'clever' tricks pretty quickly and undo them all. A product is a product, a service is a service (everyone knows that)
Plus, if your items are listed as services they're no longer products and may not be eligible for some types of SERP deployment as a result of that
The real question for me is, why is Google doing this?
I think it's because, marketers and SEOs have known for a long time that any type of SERP injection (universal search results, e.g: video results, news results, product results injected into Google's 'normal' results) are more attractive to users and because people 'just trust' Google they get a lot of clicks
As such, PLA (Google Shopping) has been relatively saturated for some time now and maybe Google feel that the quality of their product-based results, has dropped or lowered in some way. It would make sense to pick 2-3 things that really define the contents of a trustworthy site which is being more transparent with its user-base, and then to re-define 'what a product is' based around those things
In this way, Google will be able to reduce the amount of PLA results, reduce the amount of 'noise' they are generating and just keep the extrusions (the nice product boxes in Google's SERPs) for the sites that they feel really deserve them. You might say, well if this could result in their PLA revenue decreasing - why do it? Seems crazy
Not really though, as Google make all their revenue from the ads that they show. If it becomes widely known that Google's product-related search results suck, people will move away from Google (in-fact, they have often quoted Amazon as being their leading competitor, not another search engine directly)
People don't want to search for website links any more. They want to search for 'things'. Bits of info that pop out (like how you can use Google as a calculator or dictionary now, if you type your queries correctly). They want to search for products, items, things that are useful to them
IMO this is just another step towards that goal
Thank you for posting this question as it's helped me get some of my own thoughts down on this matter