Ahh, the sounds of addons breaking and addon authors updating them as fast as they can.
7.3 is a pretty big patch (eight hours of server maintenance even with preloading the patch), I haven't seen this much chaos in a while. IIRC, Legion's launch was fairly smooth.
As much as I want to play, I think I will wait till the weekend for the kinks to get worked out and most of my addons to get updated (some need more than a .TOC update).