According to who? Why do you think this is somehow the case?
The contract between the two countries is only for 1 year, and that doesn't mean everyone will even stay there that long.
In what scenario does indefinite detention make any realistic sense even for the best-case scenario of its intended purpose i.e. rightfully-deported violent criminals?
Do you honestly think the US is actually sending anyone to indefinite detention who has not received a life sentence in court?
I'm not saying what's going on isn't wrong or that there aren't other huge problems with it, but your response to me just seems even more out of touch with reality than the current situation itself.
The biggest problem I personally have with this is the administration's complete lack of empathy. Not once has anybody in the executive branch apologized for wrongly deporting anyone, made any attempt at saying they should be brought back, or that they were going to try, or that they even wanted to try. Instead they're seemingly actively doing everything they can to prevent lifting any useful fingers whatsoever.