Notice it took a wall of text to clarify your post, there is a main/preferred subclass, if you end up with six warlocks, that's a failure on your raid leaders part, when we to clan runs, we all rotate characters to have a decent group comp. We do all start somewhere, putting in the work to be prepared to raid, then raiding, you want to skip the prep and jump right to raiding, be prepared to get kicked from PuGs. In this scenario, I wouldn't have kicked him because he was upfront about it, my point was this is something he has control over, quit wasting time on the forums and fix it.