EA and Valve are partnering up to put both games and EA Access (EA's subscription service) on Steam.
The first big drop for this initiative is Star Wars Jedi: Fallen Order on Steam, launching on November 15. A glance at the title's Steam page seems to indicate that users opting in on Steam will still need to have Origin installed, similar to how games like Division 2 direct you through Uplay to play.
Other big titles like Apex Legends and Battlefield V will hit Steam next year. Still want to play on Origin? No problem, you'll be able to play with Steam users.