They might have to.
I just stumbled across something: there was already an Orlando Guardians football team when the XFL decided to play. They're a team consisting of first responders like fire, police and EMTs. They play in a league called the National Public Safety Football League, which has teams in NY, LA, Orlando, Philadelphia, Chicago, Columbus and Dallas.
http://www.npsfl.org/teams.html
Now, chances are, that Guardians probably never got involved in trademarking their team name, but someone's going to end up in a legal fight. And if the government is one of the parties...
I, personally, would have made a move for the Apollos branding if they're reviving spring football names.