1.) The ones that came from Macross, which the litigatious Harmony Gold gots its fist on. Unfortunately that's where the Warhammer falls into, as well as the Marauder.
2.) The ones that comes from any other anime, and which Harmony Gold doesn't have their paws on. Nonetheless FASA took them off to avoid any potential and imagined conflict.
What we are seeing from Project Phoenix belongs to the second group. The Locust comes from Crusher Joe, the last English translation was distributed by the defunct Animego, while the rest --- the Battlemaster, Shadowhawk, the Thunderbolt --- comes from an anime called Fang of the Sun Dougram. In fact the original Shadowhawk is the Dougram itself. In this case, the Japanese creators don't seem to mind, as long as the new designs don't copy theirs. If you notice, mechs from these series typically have gun or missile packs over their shoulders.
There are four other Unseen in Battletech connected to Dougram. Two of them are quads, the Goliath and the Scorpion. Due to technical reasons, we are unlikely to see these on MWO.
The other two are more important because they are among the common grunts in Battletech. One is the Griffin and the other is the Wolverine. Both are 55 ton medium mechs though, and bears some functional repetition to the Shadowhawk. If ever more Reseens are to appear in MWO, these are probably the last two we might see.
Edited by Anjian, 03 July 2013 - 10:10 PM.