Re: FSSP
Rome's view was always that a bishop for the Society wasn't necessary - since the FSSP didn't require one as a condition of reunion, they didn't get it.
Look at Campos, though. The agreement included a successor for Rangel, and a successor was indeed given.
Good point. What you're saying is that when you're negotiating with Rome, you only get what you demand. Any concession is interpreted as a weakness. Nothing will be given to you that isn't iron-clad guaranteed in writing and public knowledge. Don't rely on them to be nice, or to keep their word if they can't be nailed down. This is good advice to keep in mind, and we should be thankful that the FSSP have demonstrated this for us.
Look at Campos, though. The agreement included a successor for Rangel, and a successor was indeed given.
True. So negotiate first, because once you're in, the die is cast and you're not getting anything that wasn't already guaranteed.
Traditionalists don't get bishops because their view of Catholicism is incompatible with the revolution. Campos got a bishop because they demanded it as a condition for regularizing their status. The FSSP don't get one because they sold their birthrights cheaply for a mess of potage. The truth is Rome is not interested in giving Catholic Tradition any more viability than it already has. It wants to destroy Tradition ultimately, not preserve it.