Out today. Probably already out now, I'm about to check my Xbox for the update.
https://www.youtube.com/watch?time_continue=50&v=6CeFSCa_m6I&feature=emb_title
72 racers competing in challenges and races in a shrinking zone. If you beat someone you can take their car or upgrade your own. Impressions have been very good, which is not surprising considering it's Horizon.
Free update also adds more cars and single player content.