It’s a dick move for sure, but the clawback of unvested shares is vicious. Not possible to know the total worth without being privy to the employment contracts of those let go, but for a single senior employee of long tenure it might constitute a 6- or 7-figure rip-off. Depending on the number of staff let go, the amount of options each held and what their strike prices were, this layoff could potentially constitute a clawback of options that would have been worth tens or even hundreds of millions of dollars of Sony shares.
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.