This is a page from the Cascading Style Sheets Working Group Blog. Some other places to find information are the “current work” page, the www-style mailing list, the Future of CSS syndicator, and the issue list on Github.
Do you want to know how the CSS WG works? Fantasai has written about:csswg, An Inside View of the CSS Working Group at W3C.
@font-feature-values object model, with change from string to numbers.
@font-feature-values is an at-rule. (It is.)
font-feature-settings: none.
text-decoration set and font-variant non-normal, then we synthesize superscripts and subscripts, and text-decoration follows those metrics.
font-language-override feature to level 4.
text-underline-position: alphabetic and auto.