TNG, DS9 and Voyager
can't be released on Blu-Ray.
Not as they are now, anyway. The effects, plus all editing, for all those series was done on videotape. That alone makes the shows impossible to release on Blu-Ray, because the maximum resolution of videotape is so low. To release these shows on Blu-Ray would require all the effects and editing to be redone from scratch. Since those shows all lasted seven seasons each, the resulting workload would be so heavy that I doubt that it will ever happen.
, on the other hand, has actually aired in full HD, so I can only assume it could be released on Blu-Ray right now. It will probably be the next, if not the only, Trek series to have this done (after TOS of course). It'd definitely require the least amount of work.