The only time I will find acceptable the presence of an online service in a mostly single player game is when it complements it, and will still operate gracefully if disconnected.
Fuck these games that just stops working when they pull the plug on the servers.
Phantom Fury was listed but they decided not to publish on GOG mere days before release. They thankfully changed their mind a couple of days ago, a bit more than a month after the release.
What’s the point of paying for early access if need to pay again when it’s stable?
Early access users took a gamble of paying a low price for a likely buggy game, that might evolve over time through user’s feedback and that has a possibility of failing and never come out of early access.
Asking for the early access users to buy the game at full price is a slap on the face.