I like the term Bootquel. Though I think Superman Returns would also fit rather nicely into this category. There were four Superman movies starring Christopher Reeves. Rather than being a full out reboot, then fairly recent Superman movie akwardly picks up as a new third film, following the continuity of the first two films, but disregarding the third and the fourth. Best I can tell, this was only done out of sheer laziness in not wanting to retell Superman's origins and not as part of an effort to avoid alienating the faithful fans of the originals.

The newest Incredible Hulk film might also fit in there to some degree. The film Hulk from the early-mid-00's sucked so badly, that instead of making a sequel, they decided to reboot the thing all over again just a mere few years after the first reboot. Instead of retelling the origin, they let it work as a semi-sequel. Retelling the whole origin story in the opening credits, and starting the character off on the lamb and hiding out in South America. Interesting, South America is where we last saw him in the completely unwatchable Hulk. I am guessing they did this so if you happened to somehow like the first film, you could call this one a sequel, and if you didn't like the first one, you could consider this one the first one. Fortunately, the new film seems pretty awful itself, so none of this really matters.

But I am thinking the bootquel might be a broader category than you realize. I think you have coined a very useful term. It is about time we broadened our vocabulary of words explaining some of the crazy new trends Hollywood has discovered in milking old ideas to their fullest potential before, god forbid, actually having to think up something original.