Sure that will absolutely happen, if its implemented poorly.
Correct implementation means things like…
Every league has appropriate rewards. If you play in Epic league, the rewards aren’t as grand as in Legendary or Mythic league. End of tournament gold, token, items, and so on all get bigger and better the more impressive league you play in.
The goal is you should want your players to play in the highest league they are capable of playing in, to get the best rewards. But at least this way, for those who didn’t pay $200+ or more on this new update to instantly become Pay to Win full mythics, those players aren’t completely being crushed and therefore won’t be instantly quitting out of games when they bring their epic/legend Mech in a battle against a 2000 hp+ Mythic machine.