Mario & Sonic at the Olympic Games Tokyo 2020 will launch for the Nintendo Switch in November of 2019.
A gameplay trailer shown during the E3 2019 Nintendo Direct confirmed this release window.
The E3 trailer showed characters competing in a handful of new and returning Olympic events.
These events include: track and field, soccer, surfing, skateboarding, karate, rock climbing, boxing, equestrian, javelin throw, swimming, rugby, fencing, rowing, badminton, and gymnastics.
It seems that many characters will wear different outfits depending on the event they are competing in.