I feel like "not suspicious" would eventually become an impossible bar.

You'd find a code pattern that was being used, and declare it suspicious.

Rinse and repeat, as people are still going to try getting around the rules.

Eventually you're left with some weird subset of a subset of a language that's legal to write iOS apps in.

In this case suspicious code is anything that achieves a fairly narrow subset of possible outcomes so I doubt it would come up much.

It’s a common fallacy to assume infinite worlds result in every possible world but 1, 10, 100, … is an infinite series but is only covering ~0% of possibilities.