Of course, there have been plenty of times in history humans have intentionally not seen sentience when it was economically or politically inconvenient not to.

Of course, there have been plenty of times in history humans have intentionally not seen sentience when it was economically or politically inconvenient not to. Even now, lots of people categorically reject the idea that any non-human animal could be sentient because it'd be costly and inconvenient to acknowledge that. I fully suspect we'll do the same with AIs; one hopes they won't ever be in the position to do the same to us.