Is it safe to download an app from the App Store without a dedicated page?

Because folks can still continue to use the app that they downloaded or that they bought.

I’ve got a bunch of books that are in this state, too. The book store page for the book is now little more than a placeholder download link as the author or publisher or whatever changed some details, but — since I bought the book — I can still re-download it. Annoyingly, it’s left me with two separate collections for the same book series, when the books were reloaded into the store differently.

If you want to find things to be fearful of, you will succeed. And advertisers will offer things to be fearful of, too. This case isn’t it. Or given how much this concerns you, delete the app.

That usually means the app has been retired, or has been retired and replaced with a new app.

If there’s malware involved, Apple can revoke app access remotely.