They bitch about the obvious reddit stuff, but do they realize that most of their content comes from reddit? What happens when most of their posts disappear?
I wish I had an actual statistic, but it's definitely not most. It is quite a large, active community, and they seem to vastly prefer content submitted directly to imgur. I would expect that few will even notice a difference, honestly.
Imgur has its own community. By now you can't even tell if something is posted on imgur and someone submits it on reddit or if a reddit user uploads something and it gets upvotes on imgur.
I think that imgur can exist on its own and will have more than enough content.