Making arena harder for endgame players with tons of L heroes is fine and dandy. I mean its easy to say they like the challenge but this crazy difficulty is going to turn off a lot of new players with the only viable source of gold farming eliminated. Considering that gold is going to be a lot harder to come by for boosting and +1 stone events, i do wonder about the potential ramifications for new player turnover.
I do hope the arena change is evaluated further before you hastily cast the decision to make it permanent down in stone. Otherwise, there has to be an alternate way of getting gold. As a considerably new player myself, who started playing 1.5 months ago, I can honestly say that I wont even be bothered playing this game if i started out now if gold is going to be such a pain to gather and its now limited usage (exception of boosting) cos buying the non-crown stone packs is really more of a gamble of luck rather than anything else.
This is especially so when cks are so very very difficult to get unless you are very lucky or manage to to get enough crowns to buy out the lotto. Always remember that a game cant survive if it cant attract new players and this, to me, seems like a roadblock to potential new players rather than anything else