Pickleball
Mud/obstacle course racing
Cross country running
crossfit
Futsal
Also, I'd like to see a modern decathlon where the 10 events consist of a variety of sports not just track and field events. Something like:
-3 point shooting
-18 holes of golf
-swimming (medium distance)
-bike event (medium distance)
-800M run
-some sort of throwing event (e.g. baseball, javelin)
-225lb bench press
3 other events from sports with broad participation.