No idea but you're right, the entire list of 200 top derbie racers all has green arrows showing how they've gone up in level and all have jumped a LOT of places to do so 🤔
It must have been a glitch because it’s back to normal now. I remember one neighbourhood called The Scream which has always been in the leaderboard (the name just sticks with me), but wasn’t when the +2000/+20000 thing happened. They are back now.
I really don’t think these leaderboard hoods cheat at all. Rather, I think they are super competitive hoods, with members dedicated to derbying, and they spend a lot of diamonds to finish tasks quickly without trashing very many tasks.
I imagine there were a lot of messages sent to support by those hoods on Monday!