Yes, anything that is installable now will continue to be installable on all versions of Julia. This change only affects registering new versions of packages. If you don’t maintain packages or don’t plan to make any new releases any time soon, you don’t have to worry about it until you do. The warning is mostly so that package maintainers who do want to release new versions of packages are aware that there will be a new process and it may be a little bit rough. Don’t plan things so that it’s crucial to your life to get a new version of something released on Monday.
From the docs it is not fully clear for me howto tag a release. Registering is done using a PR or issue, but how is tagging done?
@Nishanth_Kottary, care to field this one?