>I want the DJ audio to be livestreamed inside various VR worlds, so that everyone always hears the same audio, but I also want to upload everyone's programs a week in advance. Each file would be scheduled to start at a specific time
Someone sends you files in advanced, and then you want to stream those files?
Edit: I'm not 100% sure I understand you right, but if you want radio check out https://libretime.org/
You can do the schedule, upload file per slot and they play automatically. But you can always take over live. If you stop sending live the pre-recorded files will play again.
You could stream to twitch if you don't mind random people are watching.
I think you can stream to youtube and and make it private. Not 100% sure.
I have a selfhosted instance of https://libretime.org/ Which is audio only and you can stream direct from traktor to it. But it's a bit big to set up first time.
There are smaller radio services where you can stream a few hours for free or unlimited for a small amount.
I wonder if you could use a meeting application like Jitsi Meet or similar.