Author of open-pdf-sign here. AdES alone is difficult to do without proper signatures and user verification.
Besides that, if Google would go for advanced electronic signatures, I'd expect it showing up in the EU Trusted List, which it isn't. So unless Google is not utilizing their own Google Trust Services certificate authority, I'd say it's unlikely that they will launch with AdES that are compatible with eIDAS.
In other words: is strictly less useful than a "fake analog signature" script that uses imagemagick to paste a PNG/SVG with a signature (or a random one from a directory of signatures) on the last page of the document, and then to apply some or all of random {sub-2deg rotation, tiny gaussian blur, tiny non-linear transform, color threshold, strong desaturation}, to make it seem like the document was printed out, signed, and scanned back.
I skip the script and (if they bother asking) tell people I have a really good scanner, a really good pen and am incredibly consistent with my signature even when I sign totally different sizes.
I don’t have any inside info here, but anecdotally, Google seems good at meeting regulatory requirements. I wouldn’t be surprised if it does meet this if it’s available in the EU.