Last I heard someone explain the closed doors was Trey Gowdy. He said they would avoid the circus and posturing for the camera, plus they feel the witness may be more candid.
Doesn’t mean they won’t have him do it publicly. I think it may depend on how forthcoming he is.
Just my recollection.
I’ll be ok with the closed door hearing if when it’s over they march him straight out and on a plane to GITMO.