https://www.gamespot.com/articles/e3-2018-super-smash-bros-ultimate-makes-you-pick-s/1100-6459761/

Nintendo revealed a ton of details about Switch's upcoming Super Smash Bros. game--now known as Super Smash Bros. Ultimate--during its E3 2018 Direct presentation. The game makes a huge assortment of tweaks to the series, but one of the more notable is when you'll be choosing stages, or so it appears.

As shown during Nintendo's Treehouse livestream, it seems that players will now choose a stage before picking a character to use. This could be a particularly big change, as before, players could select a level that their opponent's fighter didn't fare well on. This approach helps put everyone on even footing before the match begins. However, it's not clear if this system will be in place in the final version of the game.