Looks like Tim Riker is driving it. He's been the main maintainer and name behind BZFlag ever since I can remember..

He holds copyright, but to my knowledge he hasn't been an active contributor for a very long time.

(At least I remember reading a discussion on BZFlag licensing a decade ago, when his inactivity was already noted. Looking at the commit log, he made 9 commits since 2011 and they mostly concern licensing.)