Tough one. A resignation is surrendering the shop. I would when the rot is so deep as to make zero differences and then go John Galt contracting.
In this case it would be surrendering and turning over subordinates to evil. By remaining in their position they can at least reduce the damage done. Most of the enlisted people and young officers cannot resign BTW.
The problem isn’t these admirals not resigning. Its having a POTUS who would make such an evil statement.