The good old YFOV config tweak from Unreal Engine 4 works with the City Sample demo of Unreal Engine 5 used for The Matrix Awakens experience and released by Epic earlier this month. The screenshots feature the unofficial version where you get to fly around as Superman, which can be downloaded via the links offered here. The download is around 20 GB.
After having launched the demo at least once, go to %LOCALAPPDATA%\CitySample\Saved\Config\Windows\ and open Editor.ini in a text editor, then add
[/Script/Engine.LocalPlayer]
AspectRatioAxisConstraint=AspectRatio_MaintainYFOV
and save.
I'll keep this post public for a wider reach :)