My first guess would be that the generator could dynamically establish references between the room manager and its associated doors.
Another idea is that instead of direct references, a messaging or event-based system can be implemented. Coms would be via unique IDs or channels. The manager would send a message when the conditions are met, and the doors would listen for that message. The Lyra project has a messaging system plugin that you could check out. E.g.: all actors of a ‘block’ could be assigned an ID and the rest of the message would be the event. Something like a string ID_MESSAGE could be passed.