Damn, that's one bold statement with pretty much no proof that is the case.

Activision / Blizzard obviously realizes that fortnite is doing well, and could ramp up development on some new future competitor, why would fortnite be a reason to cause layoffs? They could react in a slew of ways to combat the issue, layoffs simply put them in a position where they can't attack.

There are layoffs in the game industry because there are always layoffs in the game industry. Ramp up when starting a game, hiring through building it, firing after it's out and stable and at a cadence when you don't need all those silly game makers to just keep the ball rolling.