Lock crystals behind a paywall like an Episode Pass? Hard pass. Personally I would much rather have this guaranteed form of crystal that is f2p accessible than something as volatile as the episode pass and whatever CG chooses to lock behind it. The crystals are the only motivation I have to do fleet arena and they further motivate and reward players to build up their fleets.
While I agree the mode could be more interesting, I don’t think removing the prime incentive from it is a good way to do that. CG needs to release new ships to shake things up in the meta so it doesn’t feel so stale anymore. Taking away crystals is not the way to go and would not make the game mode more interesting.