I still have a theory that the acquisition of Marvelman into Marvel Comics may effect Carol and her name. If Marvel wants the Marvelman character to be a big deal, and I think they do, they may not want a "Ms. Marvel" character who has no connections to Marvelman. Especially if Marvel wants a Marvelman "family". I know there was a Kid Marvelman, a Young Marvelman, and a Miraclewoman. Will Marvel Comics be using such characters in the future as well? Quite possibly. So if there is a Miraclewoman/Marvelwoman character, would a Ms. Marvel character be redundant? I don't think so, but Marvel Comics may not see it that way.
So maybe Ms. Marvel got canceled not to relaunch her as Captain Marvel, but to relaunch her under a completely new name?
Of course, Spider-Woman isn't really related to Spider-Man, so I could be completely wrong about this theory.