Formal/persistent organization and people trying to be leaders are generally frowned upon in antifascist scenes. It’s partly due to the anarchist current in them, but it’s also because antifa is something you do not something you join or something you are. Someone may lead an event or something but it will reject someone becoming “a leader” instead preferring those who would be leaders be seen as people having more experience
In short your local lgbt community may have a group with a president, that’s normal. Your local antifascist community almost certainly won’t.