I'm not great with copyright law. I'm not a lawyer. But I do know that the Dungeons & Dragons System Reference Document (SRD) is of vital importance to third-party creators.
SRD 5.2 allows creators to utilize the updated core rules to publish their own TTRPG content and keep full ownership and control of their creations.
Basically, it allows creators to publish their own adventures, supplements, settings, and other game materials without infringing on Wizards of the Coast's intellectual property. It outlines what mechanics, rules, and terminology can be used.
How ability checks work, how combat is structured, how spells are cast, and what appears in stat blocks for monsters; these kinds of things are all included in the SRD, and gives creators the means to build new content that is compatible with official D&D, making the third-party creator's content instantly familiar to D&D players and Dungeon Masters such as myself.
This updated SRD 5.2—which is mostly D&D 2024 Monster Manual stuff, but also contains 2024 Player's Handbook and 2024 Dungeon Master's Guide stuff—is licensed under the Creative Commons Attribution 4.0 International License which, if I understand correctly, means that it will always be available free of charge. This is how you can visit online shops like the Dungeon Masters Guild, DriveThruRPG, or even Kickstarter, see hundreds of D&D supplements, and know that if it says it's "compatible with fifth edition" or "5E compatible," then you can slot it into your 5e D&D game with relative ease.
All of this is boring but important. It keeps Wizards of the Coast on good terms with players and content creators after the Open Gaming License (OGL) scandal/controversy/debacle sparked outrage across the D&D world in early 2023. Some of us are still recovering. While others will never have their faith restored in D&D publishers Wizards of the Coast, or WotC's parent company Hasbro.
Suffice it to say, the D&D SRD 5.2 being updated under the Creative Commons License is a very good thing for the entirety of the D&D ecosystem. Keep playing.
You can download the SRD 5.2 right now, if you want. It's not beautified with WotC's incredible stable of artists. But it's got the guts of D&D 5e all up in it.