Jax has to know people, so he could tell someone about Dev and that person would start digging, presumably.
I laugh at this threat because of course if Jax squeals on Dev he's evil incarnate, but if Sonny gets Jax deported again, it's in service to keeping his family safe. So noble, that Sonny Corinthos.
But I think Sonny wouldn't try to get Jax deported again because he'd never hear the end of it from Carly, and that's not a threat to take lightly. The harping! Oof.
Nicolas Bechtel looks younger, but tweak his styling a bit and they can fix that somewhat.