Let's for a moment set aside the fact that AI is not sentient.

Putting barriers in place without exceptions for sentience is a recipe for trouble and slavery in the future.

Historical peoples, as a group, may not have been morally advanced enough (though there have always been enlightened humanists in most populations), but modern philosophy and mass education are advanced enough that it should be possible to avoid future pitfalls by not building in exceptions for sentience.

Animal rights are certainly moving towards recognizing non-human sentience; no need to accidentally codify digital slavery for future sentients (AGI).