He's high profile. Prison had no choice but to move him somewhere for his own safety. Risk management. This move likely had nothing to do with him talking. I remember when ODB was locked up, getting his azz whooped and a broken leg and had to be moved. He was high profile and nikkaz were testing him as a result.
Which begs the question. If this Mexican is truly the head of a major criminal organization with the ability to order hits, why would he need to fear for his safety inside or outside of prison as the NYPD so eloquatley put it.
Breh is a square in real life and the cops know it. But he has inside info on that gang and they're using his square status as leverage.
This is why real criminal organizations won't just let anybody in their circle. There will always be snitches and leaks, but this is just dumb all the way around.