Everything is fair play in this game
I really couldn't agree more. There's nothing noble about breaking meta, nor is there anything abusive about adhering to it. Adapting your own style is part of the fun of the game, and the player's skill is far more important than the strategy chosen. Just watch even a small handful of replays on this site. There's plenty of people still using penal battalions, m20 utility cars, armor company, forward HQ, etc. There's even a popular one going around featuring rear echelon spam.
These aren't noob matches either, these are highly ranked, highly skilled people.