I heard they are going to make the ball square in the sequel.
Boy do I have some news for you.
Rocket League is in desperate need of a change, but I honestly don't see how they can do it. The only people who still regularly play are generally insanely good at the game, to the point where newcomers are often intimidated and discouraged to play. Hell, I've been playing the game since it released, and I still don't like coming back to it because of how much the meta has changed to arbitrary technical skills that require hundreds of hours of practicing. (Even though that's precisely what I loved about Super Smash Bros Melee, but that's also an accidentally perfect game...)
The only way they can have a successful Rocket League 2 is if they shake up the technical gameplay enough that it leaves room for newcomers and returning players to have a chance against the ultra tryhards.
Actually, speaking of Smash Bros, that would be a great way to do it. The Melee tryhards like me still play and enjoy Melee over the modern Smash Bros games, but they're still extremely successful. The core gameplay is the same game-to-game, but the technical skills you need change drastically between games. And for some people, that means they'll just stick with the older game, and that's fine. But changing up the mechanics would probably help bring more players in than the ones they'd lose.
Or maybe I'm just salty because I've played this game for 1300 hours and I still suck balls at it.