Luckily, I always check the community hub on Steam while a new update is being downloaded just to play it safe and people are not happy right now.
And Yeti, so far no one other than you has said they're not having the problem over on Steam and I haven't even started the game to find out if it happens to me, I'll just play something else while I hope they get a hotfix out asap.
I really need to disable Steam from updating games without consent first, I believe auto update can be disabled. at least I hope it can be. Skyrim downloaded a really crappy patch a few months back, which they fixed a few days later I believe but there's still a few left over issues they're just not game breaking ones.
I also need to disable Steam from syncing saves, I believe its causing SRIV to freeze when exiting. It's only happened twice but both times it happened, it was right after I deleted save files and that makes me think Steam kicked in the syncing thing before the game was fully exited causing the lockup. I could be wrong but Telltale's Walking Dead game had a few glitches when I had Steam set to sync save files and disabling it got rid of the glitches.