There has and never been a reset. Just another one of those stupid theories people crop up, like the coma one.
By reset, I mean how Ash's battle smarts are radically different. I don't mean there really was one but it seems like Ash doesn't know this or that or is significantly dumber because, say it with me, the plot says so.
You got that right! The Legend of Korra is returning on October 3rd! Mark your calendars!