To get as many trainers as possible to join PvP I think they will introduce Sinnoh Stones as a reward. In what way would that be implemented? You wouldn´t want to see people starting to drown in stones.
My guess would be extra valid if you must meet in person to PvP.
> if you must meet in person to PvP
I really hope not! It is fine to have to spend some time on the street to find Pokémon, raid, and trade, but I would like to battle when relaxing at home. Already now, I need to escape 15-20 minutes from work to do a raid, then add 15-30 minutes for trading and then battling? Plus I live in a different place than all of my in-game friends...
My guess is that for battling, the rewards have to be comparable to what one would get from grinding. A few hundred dust, maybe equivalent to a poke stop spin, and then some win counter that will likely have a badge attached to it, probably one for each league. Idle speculation that you need X wins in the Great League (CP < 1500) to enter the Ultra League (CP < 2500), and Y wins there to enter the Master League (no CP limit).
