official release

Well they apparently had, or still have, communication with Bethesda. So both they and Microsoft have obviously been fine with it so far, that doesn't mean they can't change their minds of course, but considering how many of a game's lifetime sales are done as preorders or day one, I don't think they're too worried about Skyblivion affecting the profit from the remaster, since most people don't have a PC, aren't aware of it, don't care for it, or aren't patient enough to wait for it to release.