Moon Studios has always been independent.
They didnt cancel the Microsoft partnership.
Microsoft did.
The excuse that they wanted to make a cross platform multiplayer game doenst hold much water considering both Oris are multiplatform and MS is effectively a third party developer now.
They also had a publisher for No Rest For The Wicked, its not like they were always planning to self fund and self publish.
Private Division was their publisher, but Take-Two got greedy and decided that publishing smaller titles wasnt worth it and wanted to focus on AAA experiences and Mobile games.
So Private Division became a skeleton company but still had the publishing rights to a bunch of games.
No Rest was far along enough that waiting to see what Private Division was gonna do with the publishing rights just wasnt tenable, they had to find a new publisher or buy the rights back themselves and then start hustling (what they are doing right now).
If the game is received well in EA theres a good chance another publisher comes along, but if people review bomb the game, then that looks less likely and they have already spent so much buying the game back from Private Division.