I disagree with you on this one, although I think you've got some valuable stuff in your other points. Digital history actually facilitates interdisciplinary work in a lot of ways. One of my first independent research projects was a digital reconstruction of a ruined Irish cathedral as it might have looked 800 years ago, and then using that model to track how it changed, and what those architectural changes reflected about shifting perceptions of ethnicity. So there you've got history, art history, graphic design, anthropology, and maybe a few more social sciences to boot.
I have to admit, I'm not a big fan of the digital revolution. I'm mostly a paper person, myself. But the tools these developments give us are actually extremely valuable in breaking in some new ground, not just teaching the old, worn-out stuff.