It is still possible to taunt off of a ledge, and move around with the taunt animation still playing. It's a common glitch that's been around for ages but still has no definitive fix implemented. In all honesty I believe they do not want to fix the glitch. For example, they have found a way to completely fix this issue with the high-five-taunt. You cannot fall off a ledge while doing the high-five-taunt as it will place you 2-4cm behind you where you actually activated it. Trying to then glitch the geometry and time it right is, well.. Impossible, unless of you course you have a script that has another way of doing it, similar to a Civilian animation glitch.