I have experienced all of the problems mentioned. Firstly there was the "disconnection without warning but can immediately rejoin" behaviour (i.e. no initial moonwalking and no subsequent rollback). Over the past two days though I experienced the other two problems. One problem being involving moonwalking characters a minute prior to the disconnect and then subseqent rollback - you can't create games for 5 minutes or so. The other problem is where your attempt to start a new game is ignored and you are taken back to the lobby as if you cancelled the request.
All of these problems are due to private duping exploits by cheaters/hackers/paysites that rely on forcing a game server crash. Unfortunately that server was hosting your game as well as many others at the time..
There's little point complaining about it since Blizzard won't ever fix it but it's useful to know what is going on and why it is happening so you can take some precautions. My recommendation is to roll with the punches. To minimise losses due to rollback, immediately leave any game and rejoin whenever you collect an item you don't want to lose. It one character is being rolled back (can't join any games) then play onther character instead for 5-10 minutes instead until the rollback completes. It certainly sucks when you lose items and progress though,
