Can't change poses yet. They haven't added the 3D view yet back either. Give it time.
Maybe 1 year later or more... who knows? but Blizz would say 'soon'.
Can we please get a blue post on this? A lot of us are stuck in these dumbass poses and can't change them. What's it been, two years now and yet another promise to fix something and nada. Any good coder worth his salt would have this fixed in a day.