I guess I'm just not seeing the ambiguity in the updated rules, probably because I'm not seeing where it says anything about "remaining hidden." The Hide action says you gain a condition "while hidden" (which is just the phrase "while hiding" written in passive form). The DM determines when hiding is allowed.
The main problem I have with the new rule is that the wording is still split between two parts of the rulebook instead of being collected in one place. To me, the actual wording itself seems pretty straightforward.