A recent message came across about vit being scheduled for autoremoval from the packaging system due to its dependency on Urwid:
"vit 2.0.0-1 is marked for autoremoval from testing on 2020-04-22
It (build-)depends on packages with these RC bugs:
938759: urwid: Python2 removal in sid/bullseye"
I'm the vit maintainer, but don't handle the Debian packaging stuff, I'm not even exactly sure who does. However, I'm guessing this is a straightforward fix, to swap in the already existing Python 3 Urwid package:
https://packages.debian.org/search?keywords=python3-urwid
I hope whoever is in charge of this makes a fix in time, it would be a shame if vit didn't stay in the packaging system.