Technically, it's very possible. Will it be done? What are the estimated sales figures when combined with rescanning and remastering costs, new f/x if needed, etc? All they need do for the most part is re-scan the original negs and splice in, if desired, the new CGI effects. Or re-render them if the assets still exist. Given how grainy the original f/x are, even remastered in 1080P, it's easy to see why new effects were made in many cases... While TOS's remastering is comparatively simple, the next best comparison might be TNG: TNG had remastering going back to the original negs and put back together- quite the task. Sales weren't as great as anticipated and a lot of customers were griping about the price, forgetting the MSRP was lower than the DVD (yet shelf price was generally half that for each season), the Blu-rays had far more added material, and - of course - the full remastering process. Customers got a steal.
I'd still rather see DS9 and VOY remastered. Heck, ENT got remastered from the film negs and they just spliced in the original effects, upscaled-from-720P. True, 480i to 1080P would be harsh for the f/x, 480i to 4K progressive would be a lot more harsh, but they wouldn't look much more generic than TOS's rendered CGI... the only remaining issue is how to deal with CGI put into live action and not just phaser blasts but all the interspacial multidimensional life forms - soft and fuzzy cgi atop professionally scanned/remastered film elements may or may not have issues of its own...)
