“I don’t know what you were trying to say, but veterans do not need to be covered to salute during the national anthem.”
Its simple, Marines do not salute unless they are covered: wearing a hat.
You think that all ex Marines will refuse to salute during the raising or lowering of the flag, or the playing of the national anthem because they aren’t wearing a hat?
If they choose not to salute, they can still put their hand over their heart like other civilians.