I don't know either, but it seems like approximately 100% of the reason game studios opt not to self-publish in this day and age is that lift. Annapurna's name alone carried a lot of clout.
(Side note: continue to be disappointed that they didn't brand themselves as "Annapurrna" on the Stray opening screen.)
I'm trying to imagine what their role is ... if you can just "be a publisher" or if you need a lot of cash up front or what.