I don't think anyone can change avatars right now, it's one of the features that cannot be turned back on until all the wrinkles are out of the new update/
Be patient, it won't be long.
I think the Zipperman has started an "Avatar Withdraw" special meeting
here at Whiners. I can feel him fidgeting all the way to Canada 
Okay, okay, so I am fidgeting too. A lesson in patience is all we need.