Hm, that's the question. I suppose she could get some kind of "lateral promotion" that lets her retain her title. The one thing that makes me dubious about a promotion is the lack of time. We'd have to see her working a new case, cleared of the civil suit charges, promoted, and Raydor brought in as the new head of the Major Crimes squad -- in 60 minutes minus time for commercials. They could dispense with the new case, I suppose, but that still leaves a lot to be crowded into the last episode.
But suppose all that does happen, what would be a good last line to be uttered in The Closer? Maybe Raydor addressing her new squad for the first time: "Now, there are going to be some changes around here."