I’m on your side but they likely make a substantial amount of money selling diamond portraits or random portrait bundles and legendary portraits are already the most difficult to come by. check out the merc store or this thread One Merc Skin in 200 Packs ($250) - Singleplayer Discussion - Hearthstone Forums (blizzard.com)
I don’t see them doing any more than they have (and potentially promised re: coins) to make the game more f2p friendly. I already feel for anyone who has missed or will miss events as now those once free legendaries are going to be clogging up legendary rolls for who knows how long to come.
also I agree regarding the n’zoth portrait except I actually prefer the gold animations so I lucked out with that being the gold portrait I got.
I have all mercs almost all acquired through packs and the only diamond I have that wasn’t acquired through events is rexxar’s and the only reason I use it is I don’t have any of his gold options.