I haven’t played in a few years but this is how I remember the system working: RDO matches people into separate lobbies based on what version of the game they’re running and this check is done by hashing one or more files in the install directory. By adding junk data to one of those files you more or less guarantee that you’ll only ever encounter other people who have the same junk data added. It’s basically the dark souls password system with extra steps.

in '86

I don’t think that has been the case for at least a full console generation, maybe more.

Look at the rise and fall of pre-order goodies to get a rough estimate of when publishers really, really wanted you to buy the game day 1 (and when it stopped mattering as much)