Does Apple TV 4K support 21:9?

I found a thread on this topic which ended in 2017, which seemed to indicate Apple TV did not support 21:9 content. Now that's it's 2021, and I have the Apple TV 4K, I would like to better understand if it does, and how.

In Settings, I am able to select 3440x1440 as a video format. However, somewhat strangely, all the content on the Apple TV screens (home, setting, etc.) just appear stretched horizontally, which raises the question as to whether it's truly rendering in 3440x1440.

How does this then affect content via any of the apps (Disney+, HBO Max, Netflix, etc.)?

Amit