This was talked about by Phillip Shoemaker (head of App Store Review 2009-2016) in this talk[0], where some developers figured out that if they hired marketing firms to commit review fraud on a competitor’s app, their competitor would get terminated because there’s no clear way to actually attribute the fraud to the developer.
I guess the App Store fraud prevention team hasn’t necessarily found a good solution yet.
0: https://youtu.be/tJeEuxn9mug?t=22m57s&si=CVfkqSqEULyFTx-8
If the fake reviews are indeed the reason why the apps were taken off the store, that does strike me as an inappropriate action. Take down the reviews, yes. But closing the developer account creates a big opportunity to eliminate competition by buying fake reviews for your competitors. There's also nothing developers can do to prevent this since they can't curate or reject reviews from what I know.
That said, other commenters are pointing out a very large revenue figure relative to the popularity of these apps. That smells more like money laundering or fraud. In that scenario, Apple should have been more specific in their communications.