The GOG release was delayed until last and came with a note: “However the multiplayer component will not be ready at launch; we expect it to be released later this year as full multiplayer parity remains in the pipeline.” There were a few other statements duplicating this information including a line near that the end that Hello Games is “joining forces with GOG.com …”
“This will be free for all players, with no microtransactions. Take part in community missions and unlock new rewards and customisations.”
Not knowing what the “rewards and customizations” will be means that we cannot predict how much valuable technology, items, etc., GOG uses will not be allowed to earn if some provision is not made to accommodate those denied access to game features.
It is also noted that a firm commitment was not made and phrases “we expect” and “remains in the pipeline” are general intents and not firm commitment to return GOG users to the community. Obviously there is a lot of hate and discontent in the GOG forums over this and these are typically forums with few posts on a weekly basis. There is a statement near the end “Hello Games is however joining forces with GOG.COM to introduce full multiplayer via the GOG Galaxy platform” which provides some encouragement but that is not a commitment that this will work or that GOG players would not be left behind when everyone else receives weekly “rewards and customizations.”