Since all TH 10's are bored or burnt out
This would obviously take Supercell awhile but maybe not as long as we think since root code for game is in place and running efficiently.
Let any fully maxed (this means everything) TH 10 move into a Pro Only verison of CoC. An entirely separate game with only high level players. Of course, this new game would have TH 11 to upgrade to along with other new goodies and maybe even new game play version of the game.
Not a flat layout, troops that have more advanced weaponry and power, since the assumption is that these player's troops have a long history and alot of experience. Make Clan Wars a bit different, you are lined up with an opponent and that is whom you must battle. The kicker is you get three attacks each and winning is based on percentage of damage done through all three attacks not on stars.
I will let the forum advance the idea further. I am just today a TH7 and have not seen everything but I sure read about a lot of TH10 people who are wondering what is next.