When this first came out I checked on my Pixel 7 which is on A14 already and I didn't have the apps available either.
They are now available.
So yeah, it's almost certainly on the app developers who didn't target the new API version available, not Google. New Pixels launch with new versions of Android, but you can validate the same issue on older Pixels who have already upgraded to the new Android version.
Google Messages (RCS app) does that. It even works from iMessage to Android but that is just because Google parses the SMS text that says they reacted that iMessage passive-aggressively sends and makes it appear correctly. It's not following RCS protocol, it's basic text parsing is all.
Incidentally, Google also started sending the same pass-aggressive reacted SMS messages to iPhone users for those using those RCS features, so now Apple gets the messages Android users had to deal with for years (and still do, if they aren't using Messages). I don't know is Apple is doing the same parsing or not as Google, if they aren't then somewhat ironically to Apple's intention Android now has the better react experience.
Revanced can't exist as a standalone app to be installed like from a store. Google would nuke it. It has to be a patcher. Original Vanced was a standalone app and that is what allowed Google to nuke it from orbit. It's arguable that Google ignored Vanced until the developers got money grubby and tried making NFTs, but the method they used for takedown was DMCA since it was their app just modified.
This is the same thing as ROM hacks, randomizers, etc and why they include a place to upload your own copy of the ROM rather than providing their own. Reverse engineering and modifying are legal, distributing copyright source, binaries, or blobs without the rightsholder permissions is not.
They also do have a repo for it, as well as the offshoot apps like Revanced manager, other app patches, etc. The fact it's not at the top of Google results is a Google-and-SEO problem, not a Revanced problem.
If you want a one and done app install then something like Newpipe is what you want, which is built completely on its own. Revanced is explicitly not that, it's the stock app hacked up. IMHO, Revanced is a nicer experience, but they are two very different experiences and approaches.
That shit fails all the time for false positives. Thankfully you can skip past it.
I frequently buy multiples of a single item so I do what a cashier does - I take a single version and just swipe it the number of times of things I'm buying, then swipe the whole lot in my bag. It always comes up with the video saying something like it appears there was some error in checkout (I'm assuming the video is to try to guilt shoplifters, saying hey look we have video). Anyways you can skip and ignore it. I've never had any repercussions to my account - granted if someone were to actually watch the video and cross it to receipt it would be obvious what I'm doing, but if they were to tie some sort of repercussion like banning my account I assume that would be automated (and fail just the same) too.
Funniest shit is it doesn't even call an associate over. I need an associate to badge in for my 50% coupon you stuck on the milk, but you think you saw me swipe some shit? Nah, not gonna raise any flags.
This whole thing isn't on Google. The app developers didn't update their target API so they were not available. My Pixel 7 is on Android 14 as well and they weren't available either until it just got fixed.