The first we ever heard of Primus was when Cliffjumper mentioned him. Unicron is much the same - never heard of him.

[ a shrug. theology, man. it is not really a thing that exists to them. of course, some might have believed it. Shockwave found it interesting. ]

Our Prime never concerned himself with the well being of his followers. Loyalties mean nothing to him when it comes to failure or a slight shift in morals. ...He is obsessed with killing Megatron, however.

[ he probably would, KO. ]