I had this issue as well. After I finished uninstalling the offending apps, I discovered there was an update available to prevent Windows 10 from doing this to start with, according to the knowledge base article on the update.
I believe this is just happening when you do a fresh install of the Tech Preview. I just used the ISO to upgrade from 8.1 to 10 TP, and encountered the bug where it installed apps I had already removed.
Since the issue was addressed in an update already, and I've already "uninstalled" them again, I'll consider the issue resolved, since it's the final release we'll really be concerned about.