Under normal circumstances, we would have a decent number of machines running Ubuntu 20.04 by now, probably including our login servers. But the situation is not normal, because ongoing world and local events still have us working from home, making it not so simple to install and deploy a new physical server with a new version of Ubuntu. However, it really looks like this is the new normal so we should start dealing with it.
It may or may not make sense to spend limited in-office time upgrading perfectly good 18.04 machines to 20.04 (I speculated about this back here in early August), although I suspect we're going to wind up doing some of it. I think it does make sense to install completely new machines on Ubuntu 20.04 for more lifetime, and we're certainly going to have some of those. We have what I believe is a working 20.04 install system, but what we don't currently have are any continuously running 20.04 machines, especially ones that normal people can use, explore, and see what's broken or odd. In the past actually operating new versions of Ubuntu has frequently turned up surprises, so the sooner we start doing that the better.
The obvious thing to do is to build a few 20.04 test servers. We're likely going to run Apache on some 20.04 machines, so one test server should have an Apache install. Another one should be a general login server, which would let us look into how various programs that people use behave on 20.04. We should also build a third server that's completely expendable and we can experiment with rebooting and other things that may blow up. All of these have to be built on physical hardware, since we don't currently have any virtualization environment (and anyway we'd be running most 20.04 machines on physical hardware).
(Running on actual physical hardware has periodically turned up practical problems. Since it's now eight years after that issue, perhaps we should experiment with no longer supplying that kernel parameter in 20.04.)
PS: An expendable test server is where it would be very nice to have some way to roll back the root filesystem to an initial state. This can apparently be done through LVM, which Ubuntu does support for the root filesystem, and I may experiment with it following eg the Arch wiki.
(This is one of the entries that I write partly to motivate myself to start working on something. We've been mostly ignoring Ubuntu 20.04 so far and it would be very easy to keep on doing so.)