Indeed these designs are unoriginal, but I'd say that there is plenty of logic with which the design could be justified. However I'd want to sue harmony Gold for suing! (It feels like an American tradition anyway.) I don't want any delays!
Truth is, they (Battletech/Mechwarrior) repeatedly violated other companies' trademarked/copyrighted material, and the shown Warhammer (right) is a trademark violation. Either they will have to obtain the rights or remove the material.
Truth is Harmony Gold can't stand somebody else being more successful than they are with the same stuff. While the mechs in the trailer are similar to the Destroid, they are not part of the law suit collection.
They sued then too (way, way back). Battletech pulled all references and pictures to the mechs they'd stolen from macross (Robotech). The problem is for this trailor they put them back, without getting permission of the rights holders.
Actually, there was lawsuits in the past and Battletech/Mechwarrior had to pull designs from it's lineup that where nothing but carbon copies from various anime. What is still left to fight over are a handful of designs that look similar.