The clawback in general isn’t really an issue; that’s how restricted stock grants work. You forfeit anything that hasn’t vested when you leave the company, no matter whose idea that is.

The problem is that it was Sony stock, and it’s going back to Bungie. The stock should revert to Sony. In fact, I don’t think it can be any other way, as those boilerplate details would have been included in the contract details of the initial stock grant. This makes me doubt the veracity of the unnamed source.