But they would also be doing nothing with the publishing rights if they cannot find an agreement with Microsoft. Also Obsidian has done Tyranny, Pillars of Eternity and The Outer Worlds in not too long a period and it looks like they may have something else in development.
I do not doubt that this is a universe that Obsidian may want to continue building on, but if an agreement cannot be found, they are well equipped to try something else.
It is pretty much, get something out of it now, or get nothing out of it ever, lol.