He sent his letter to the Press going outside the Chain of Command from what I understand.
That is why he was relieved.
You don’t have that right in the military.
Broadly revealing status of combat readiness is not a good idea.
That does make sense.
It assumes that he was the one who leaked the letter, but who else had a reason to do so? And in doing so he divided the sailors on the ship from the leadership of the Navy, who also claim they were working hard to address the problems he brought to him already when the letter leaked.
Also they stopped in Vietnam during a pandemic and let 1k people off the ship.
As far as I know he did not send his letter to the press, but sent it to about 20 people on a unsecured outside the chain of command.
His direct line of command was actually on his ship at the time....