Another lame attempt at ruling by decree. The CPB was deliberately designed with guardrails to avoid partisanship - the president appoints board members, and no more than five from the same party.
If you've listened to NPR or watched PBS, you know they're about as neutral as you can get while still covering both mainstream sides.
This style of governance is so lazy - instead of working through Congress to change the law, he tries to bully an independent board into doing what he wants. It's also so easy to oppose, the board can just ignore it.