RLBot is a framework to create and play against custom bots. I was able to leverage the framework to create a story mode where you play against bots to take over cities. As you win, you can recruit teammates and purchase upgrades! The features was merged back into the RLBotGUI which is the main way of playing against community bots.
Link: https://github.com/RLBot/RLBotGUI#rlbotguiRocket League Story Mode
Added Story Mode to Rocket League