It's pretty obvious at this point that good premium heroes will never be released to shops. Given the discontent this is causing with the community, that means that the devs are accepting that the game is in its decline. As players realize that the game is declining, there's less incentive to invest $ in heroes, and so it's a death spiral. Now that they won't release overpowered heroes, if a game-breaker is released in the conjuring stone (like Sylphi was), there will be a mad rush for the exit doors. I'm betting a ton of people would have quit last December if they knew Sylphi still wouldn't be released ~10 months later.