I think it's true, there was a time when too many fake apps are available on playstore and they are been flushed out one by one, there was a statement made at the time that google play store is now safe 🤔, that's a very long time ago, not sure I can dig anything up about this again, anyways its getting more risky to install apps through stores now, better start downloading from official websites
I really doubt that Google would claim something like that. They would open themselves for bunch of lawsuits if someone lost money due fake app, and people are loosing money due that on the daily basis. They might have claimed that PlayStore is safer now than it was before, which is probably true because they introduced human component when checking malicious software, but they are still not doing enough in that regard. Not even close.
In the end, they covered themselves nicely from any lawsuits. You can see this quote from their TOS, so alleged claim to be 100% scam free would go against this.
Google is not responsible for and does not endorse any Content made available through Google Play that originates from a source other than Google.
Regarding fake Atomic wallet, this is the 2nd case in last few months, that I know of. In the previous case it took Google more than a month to remove it, I hope that they will be much faster this time as some will fall for this, so least they could do is to minimize the damage and remove it ASAP. It would probably help if Atomic reports it too, or at least warns their users, but based on previous case it seems like they don't really care much about that. Last time i warned them about fake wallet, they didn't do absolutely anything to warn their users. Maybe that's the reason why scammers are using their name again.