No it is still not possible. We started to look at it before the latest CentOS Dojo in Bruxelles (Jan '20). It seems there are still many packages we rely on (e.g. Let’s Encrypt) that are not available under CentOS 8.
Can we run a Nethserver 8 beta (based on CentOS 8) in a vm to help you test (and find out where it breaks)? Is there a place where we can download the .iso?