Put me with those who think the Joneses feel they gave up too much in the current deal, and feel they proved with Jason Garrett that it doesn't scare them in the least to have an ultimatum year with anyone.
Further, I think they think there's really nothing to lose. If France and his client won't work out something with them that is sufficiently team-friendly, then the ball is in Dak's court to perform well enough in 2024 to justify a handsome offer a year from now, ie, with the 2024 DAL roster having, on paper anyway, regressed. If, however, Dak wants to have a stronger supporting cast, then it's up to his agent to work with the Joneses to make that possible.
France, too, has proven he'll play hard ball, of course.
It's been typical that these negotiations have to have some kind of significant deadline pushing it to some end for there to be one... an end. I'm not sure what that would be under the circumstances. So, yeah... I absolutely can see this being Dak's last season in Dallas, unless he decides that's important to him to keep playing in Dallas.