The Chromecast Ultra currently puts out 720p, 1080p, or 4k and I recently purchased a new monitor with 1440p resolution capabilities. I know the CCU does not currently support this resolution but are there any potential changes/updates coming that it may??? I see various other ways to get to the 1440p outside of using the CCU but I'm interested in using my CCU.
I haven't heard of anything officially, but you should let the team know of your feature request! If you open Stadia, click on your avatar icon, then click feedback and paste your post here, it should be sent to the proper Google team.
All the best!