No, the Star Trek: TMP problem was that they scanned the film in HD, then downconverted it to 480p SD and did the effects at standard def. So for the Director's Cut of TMP on Blu-Ray, they're going to have to re-do it from scratch. The negatives weren't touched. The Star Wars SE's were created with the intention of theatrical exhibition, so there's no problem there.

Interestingly, that's pretty much what happened with Adywan's ANH:R (though he worked from the SD DVD to begin with), and why that will never be in HD like ESB:R and the others will be (too much work to do it from scratch).