He can tease it and then stop and get booed
The thing is, he was a heel for essentially his entire WWE career sans the last few months. Dude wasn't really doing anything different except for the taunting.
I also think Rollins will make a more effective heel than Ambrose just because I think the IWC fanboys will cheer Ambrose no matter what. Rollins doesn't have that aura about him, so he should succeed at getting booed.