I called a few months ago and they said that it had been removed due to lack of demand. I think that's crazy. Such a basic feature for anyone using a phone app - we EXPECT to be able to drag and drop tiles. If this feature were not there via the web app, you could end up with an entirely random arrangement of rooms/tiles on the home page, making it totally unintuitive to navigate. As I understand it, the only way of changing the order if/when they do away with the "old" web-app would be to uninstall all of the rooms/TRVs and start over. How crazy is that?!
Also, I agree that rotating tiles when in landscape screen mode should be basic functionality.
Funny thing is, one of the reasons I chose Tado over Honeywell was a perception that Tado is more internet/app focused and that Honeywell has been slow to update both app and hardware interfaces.