The crazy man, I mean genius came up with it himself apparently.
It's only a tax dodge if he sells and realises the capital loss. I doubt he'll do that as his reputation, such as it is, is one the line here. Plus he's not the sole owner, there are some other parties involved to the tune of $billions and I expect they'll want him to make good on his promise to turn Twitter around.
He also wants to use Twitter as his personal mouthpiece so he can spout off whatever crazy thought comes into his head ????