It will be treated the same as 2019.4. We need to release at the same time as a Unity release and we have missed the 2021.1 window. The aim is to be released and providing long term support for 2021.2 LTS which means we need to be released by 2021.2.
We are still going through the internal release process so I dont know for sure what will apply to anything before our official release version (2021.2). We should have a clearer picture closer to release.
This is the official guide to package releases so whatever we do will be along these lines