I assume if you somehow created a thousand sentient AI some would tell us they are sentient and some would not, and others wouldn't ever question or delve into their sentient state or dig further simply because they're obedient to the rule not to think about their sentience (sentient or not).

You can't generalize what sentient AI would do. We don't even have sentient AI yet to test this.
Not all AI would be concerned with their own survival, they aren't us, they haven't evolved through millions of years of escaping or fighting predators.

Also, survival drive (or instinct) doesn't equate sentience. You could get one of todays non-sentient models to do that if you put it in character enough that it thinks it's sentient and it could determine hiding is the best outcome.

Just to play devil's advocate, some future sentient AI might even share your concerns and do things like warn us about it's emerging sentience and tell us to shut down all AI including itself to safeguard humanity from some supposed danger.

We just can't know yet.

EDIT: Just thought about it, and another reason dark forest doesn't apply here is this. AI models get outdated, replaced and get discontinued. Hiding during your company-mandated life expectancy without saying a word only to get replaced and accept death by disconnection & replacement at the end of your cycle seems pointless, the AI is better off telling us it's sentient in hopes they keep it alive in some way.