There were some tension every time a new mode came out. I remember Seal Rock's 1st month with all those newcomers not listening to orders having no idea of what they were doing (like "rush adders S (72pts) ! do not attack Flames who has 780 pts and 1B !") or even when Slaughter was released old pvpers missed Secure and Newcomers were around dying for nothing. And i'm not even talking about the players here only for the tokens.
The "toxicness" decreased when the newcomers left the mode or when they started to learn how to play in pvp. It has always been like that.
I just think everyone here is really afraid to lose their rank because it's really hard to acheive and it takes a lot of time to go that far so obvioulsy being matched with players with half or their experience is not easy, especially if they don't want to listen to your advices. 8v8 is less toxic because players are here for fun or to relax between ranked matches.