For the record, the decision is not mine, nor do I believe it's the home video department's, who I'm certain feels they'd get a bigger sales bump if these were out during the new film's release.
Because of the unique take on DS that the trailer description out there and stills seem to convey, someone in the studio or the production team does not want brand confusion. They're probably thinking of the long game here- turning this new film into a franchise series, apart from the works that came before, with the hopes that it could ultimately generate a half billion or more dollars like the Pirates series. In the face of that, several hundred thousand dollars of sales generated by the movie releases on video probably seems like chump change in comparison.
For reasons I cannot go into right now, this may all be for the best. There are things I'm working on right now in preparation for this project that are taking up a great deal of time and will need a couple of more months to play out...until I'm satisfied we can proceed in the best possible manner for the most polished possible result. Hopefully this will all turn out to be a remarkable case of fate intervening in the timing, and hosannas will be sung this time next year.