This is my favorite episode of My Little Pony. The metaphors being used here about how idolatry and monarchy are less important than genuine loyalty are very important. Gilda is a great griffon dude lol, she could have been a star among griffons, she could have become a legend to them, she chose her friend over the idol. That was big of her, and she even worked with Pinkie to make the rescue happen for Rainbow, even though Pinkies incompetence kind of got Rainbow trapped down there, she still had good insight.
Bottom line, Gilda didn't need to be banished from pony kind for being mean, she didn't try to you know LITERALLY OVERTHROW EQUESTRIA, she just hollered at and ripped on oversensitive ponies lol, but obviously her loyalty as a friend was absolute to Rainbow, and it brings more perspective on the fact that rainbows loyalty element speaks volumes about her and always has.