May be better to change the link to their official announcement: https://www.dndbeyond.com/posts/1439-ogl-1-0a-creative-commo...
See also: https://www.reddit.com/r/DungeonsAndDragons/comments/10muz3c...
tl;dr: OGL 1.0a being left untouched. Latest D&D mechanics (which have much more limited copyright-ability by WotC in the first place) are being released under Creative Commons.