To make it look, on cursory reading, like the policy is something you are comfortable to agree to. Legal theatre.

Also because those specific uses are mentioned in existing law and/or have been otherwise successfully defended. It gives their lawyers as many explicit tools as possible, before they need to argue around the implicit ones enabled by their policies & agreements being deliberately more vague elsewhere.

The point is that if they don't say that they won't, then they pretty much can if they choose to.