I'm familiar with it all. I also seen something about them not wanting to take sides. It may very well be them taking a shot at LP, and it may not be ! We don't know.
I would use a poster of LP era Chester too ( providing there's no copyright issues ) Why wouldn't you, its how chester is known to fans all around the world, not many casuals know of grey daze, if any.
Promoting this album is NOT a crime. If you want to say its a cash grab, then fair enough, no proof of that though. I would market the hell out of this thing as best as I can if I were GD.