Your son's use of that room will eventually change - a study area/nook? - but it's a firm rule that your need for closets and storage will exponentially grow over time, lol.

I would keep the closet.

His bedroom doesn't have a closet?

Can you remove one of the two closets? And, that triangle black hole on the left, can that be opened to the little hall instead of to the playroom?

Not a pro but I vote for keeping the closet! That won’t always be a play room :)

Keep the closet. I would actually have someone make a built in closet in the hallway for the space to the left of the door(when in the room) to utilize that area under the slope of the roof and then just a flat wall in the room.

Maybe you can replace the doors with either folding ones or sliding ones .

I believe that for a room to be considered a bedroom, it MUST have a closet. Don’t remove it. The room is a cozy space to play in!