Musk will take Twitter private now, owning most of it, with some shares going to banks who gave the loans to acquire it. Once, it becomes private, you will not be able to buy TWTR shares much less, short it. It will simply stop trading in the US stockmarket.
As a side note, Musk's whole 420 shtick is getting old. Really Elon? $54.20 per share? It's just so tired and peevish now. But hey, he's rich beyond the dreams of avarice. He can do what he wants. I guess his asperger's keeps him from realizing how socially doofus he is behaving. He should take some of his billions and lobby congress to legalize pot on the federal level if he really wants to make a difference.
Dumb question probably and this is probably arbed out but what about buying any dips till the deal is finalized?
It will pop and fade now for many months. Unless Elon does something silly (not like he does that ah! ;p)