The System Reference Document 5.2--the tool which helps developers create third-party content using the Dungeons & Dragons core rules engine--will be released under the Creative Commons license on April 22nd.
Additionally, Wizards of the Coast will publish a Conversion Guide for updating game content from the 2014 edition to the 2024 edition. This guide will arrive at a later date.
The Free Rules document on D&D Beyond will also be updated with new D&D Beyond Basic Rules (2024).
The older 5.1 SRD, which is based on the 2014 edition of D&D, will also remain available under both Creative Commons and the Open Game License (OGL).
More information will be available on April 22nd, when the new SRD is released.
A copy of each System Reference Document is stored independently at A5ESRD.com, which includes the 5.1 SRD, the revised 3.5 SRD, and other System Reference Documents (including the enormous A5E SRD).