Sony Offers Hilarious Excuse For Blocking Cross-Platform Rocket League, they want to protect the children. (You have to disable ad-block to see the article, sorry!) : r/RocketLeague
Sony Is The Final Piece Of The Puzzle In Rocket League Cross-Console Play - Game Informer
Rocket League RocketID cross-play delayed until 2019 to add PS4 support | Shacknews
Rocket League gets full cross-platform play after PS4 relents | VentureBeat | VentureBeat