This is the same kinda shit that Valve / publishers pulled when Steam launched, though.
Half-Life and Counterstrike originally didn’t require Steam, and then one day Valve told everybody they’d need to start using Steam if they wanted to keep playing the games they’d already bought. That’s a Valve game, but it’s akin to Epic moving Rocket League to EGS (which also pissed people off).
For more general / non-Valve games, there was a time period where you’d pre-order a physical copy of game and honestly not know if it would require a launcher. Tons of games that launched in early days of Steam didn’t bother to tell consumers upfront that Steam was required, and consumers wouldn’t find out until the game hit the shelves and there was a little note on the back of the box, “Internet access and Steam account required.” In that case, non-Steam pre-orders weren’t even given an exception – every copy required Steam. That seems even worse than the Epic mess IMO. There, the publishers at least made an exception for people who thought they were ordering a Steam game. If you thought you were gonna get a real physical copy of game that didn’t require a launcher, and it ended up requiring Steam, the publisher just told you to either use Steam or pound sand.
I don’t like the behavior either, but pulling already announced / released games and forcing them onto a different launcher is standard practice when a new launcher comes out. It’s happened to paid and non-paid exclusives. It’s happened to EGS and Steam (and probably Origin or Uplay or others too). I don’t see any reason to be any more upset at publishers over the EGS debacle than the Steam one.
My take is that launcher exclusivity shouldn’t exist, because every single launcher has just pissed off / screwed over consumers when there is exclusivity / any requirement to use the launcher.