I doubt it going to happen.
Every game has 21:9, this is 2019-2020 after all. Many games release without but within a week or two they have 21:9 support. Fresh in my memory is Disco Elysium quickly added 21:9 within a couple of weeks.
Obsidian doesn't care. They're off courting Consoles.
Edit: Just patched to 1.3, Still doesn't support Fullscreen 3440x1400. In Windowed Fullscreen still has black boarders in cut scenes.
I find it kinda insulting they announced a Nintendo Switch version, but on PC we still don't have 21:9 support.
Never again will I pre-order an Obsidian title....
So, yeah as someone that bought it on day one, was disappointed at no wide screen support, and has been waiting for it to be added so I can play it in full wide screen support glory, I also wanted to add my 2 cents. 21:9 ASAP please.