It is available as an early update, see here (at the bottom) for how to enable Early Update for this version if that is your choice: https://techcommunity.microsoft.com/t5/configuration-manager-blog/update-2403-for-microsoft-configuration-manager-current-branch/ba-p/4119853
Based on the date of that article, it was offered for early release on April 22. In my experience, usually versions of CM do not release for General Availability until at about 3 weeks after early release. So I would expect it to be general release about May 13th. BUT keep in mind I do not work for Microsoft and have absolutely no inside knowledge whatsoever. I'm just going by "in the past, what I have noticed is that it's about 3 weeks later". I could be completely absolutely wrong, and it's released for general availability 5 minutes from now.