I’m not into sports myself, but I hear a lot of people complain about predatory subscriptions to professional sport streaming servicies, intrusive gambling ads, etc. Organize free internet streaming of old broadcasts right as they enter public domain (50 years after broadcast in UK) and pretend they are going live, do discussion, bar cheering, all the things sports people do to entertain themselves, for free.
Just don’t read spoilers
Most fans will know the historic results anyway for any game worth watching. Spoilers aren’t involved.
If the matches are old enough and not major matches (e.g. championships), most people aren’t going to know the outcome without looking it up. Do you know any normal season games from 1970 MLB?
Anything post-season would be a tough sell though.