Like other posters, I also do not buy into the myth that DS9 is not popular enough to remaster, nor the similar myth that DS9 is not popular enough for there to have been a DS9 movie.
DS9 is very popular now
, probably even more so than it was when it originally aired - at least among hardcore Trek fans, who are the only ones who would buy any Trek home video products anyway.
At least one of the writers of DS9 said that it sold very well on DVD when the DVDs first came out.
Many years later, everyone who wants the DVDs already has them. Therefore, Paramount is going to have to do something new with the IP in order to keep making money from it. Remastering is one of the best ways to do that.