The blog entry noting the tagging of 6.0 RC1 and some of the highlights of what's in it might be more communicative than just the github tree.
https://www.kicad.org/blog/2021/12/Development-Highlight-Thi...
https://www.kicad.org/blog/2021/12/Development-Highlight-Thi...
[0] https://www.kicad.org/blog/categories/Development-Highlight/
[1] https://gitlab.com/groups/kicad/libraries/-/milestones/1#tab...