That would be fun.
It would also be difficult, because it seems like it would be ideal to have it at the con itself, but unfortunately, that almost always means we have to have the hotel cater it (it's in any hotel contract we sign) and that would cost at least $20 a person, if not way more.
We barely got away with having a smallish yojimbo party and ordering pizza. It worked because we did it in one of the actual bedrooms, and not con space, and because we didn't let the hotel know about it. No way we'd be able to get away with that in official con space.
So ultimately, we can't spend approximately 100 staff x $25 = $2500 minimum on a con after-party, considering that's 5% of our budget.