Any reasonable reading of this sentence, while technically it does not explicitly say that it's "completely secure", is that the review process will include security review. It's not without context that this sentence is read, and the history of software tells us what the point of such a review is for protection of the user. Being technically correct is not actually useful when deciding how reasonable people will interpret a piece of marketing material. They are using strong language to give the reader confidence that the apps are safe and they should not be afraid to use them.

Excuse me, they used the words "every one of" and "every app" to describe the purview of their security checks. Is that somehow not absolute enough for you?

Is the idea that a nontechnical person might trust Apple really that outlandish to you? Do you have, like, family members or nontechnical friends?

Idk, when I see " rigorously reviewed", I think being able to see the app is attempting to masquerade as an existing one...

We are discussing the claim that Apple guarantees every app is "completely secure". Thanks for the comment though.