Yes, free-to-play, with equal gear that has been decided on beforehand (see webpage). Unable to XP-lock, but wargames do not reward XP. There's a small amount of participants so far, so it ended up with several of the people as the same class by accident. Everyone is free to choose whichever class, only hunters are excluded.
Not sure why the rogues were removed, maybe too OP in the arenas? I did think there were some rogues.
The warriors, priests and mages are just to fill up the ranks with people who are interested in playing but haven't leveled their own 19 yet.
I think Kochi had a great idea with this! Give it a try and join in. I have a priest so far, looking forward to wargames happening.