Instead of demotion, I concern more about cumulative rewards. If you only get 10 gems per win and won't get anymore after your 50th win, it means you will only get 500 gems per month, which is only worth 10 packs. I hope it would be 20 or 30 gems per win, but knowing how Konami deal with things makes me feel hopeless
But do we know if those Gems per win will be added on top of the cumulative rewards we already had, or will they be substituted instead? I´d like to think Konami is giving us more free Gems while encouraging PvP, but you never know. They always seem to have an ulterior motive that only benefits them...