As a user who sometimes builds programs, I certainly would prefer all the qt headers to come together. A dependency relation would do that (as would making them a single package).
Since the package maintainers have said they would do this, perhaps that is still their intention. Their failure to do so already may reflect oversight (e.g., inadvertently uploading the old version of the packaging stuff) and general busyness rather than anything else. It would be helpful to hear from them. It's not clear to me that a NMU will solve the problem, for two reasons. First, we could end up with dueling uploads from the maintainers and others continuing indefinitely. Second, since the Debian-specific source is maintained at KDE (I believe), that's really where the problem should be fixed. I thought this was the kind of issue the technical committee was set up to deal with, though others (including Ben) undoubtedly have a better feel for it than I do. Obviously it's desirable to keep things out of the technical committee, just to reduce its load, but it doesn't seem to me such a big deal to use it when there is a signficant technical disagreement. Such disagreements can arise in good faith, and there needs to be some way to resolve them.