We have just landed the revamped user activation model in the HTML spec, closing #1903 and #3859. It's time to fix other specs that refer to the old activation model. (Note that the PR above fixes the references within the HTML spec.)
We will track the overall progress of the work (in other specs) through this meta-issue. Each of those other specs will still need its own tracking issue; this meta-issue will simply link to the external issues.
[Last update: 2021-Apr-15] Here is a task list for external APIs mentioned in this thread below. We will try to keep the list updated (manually) to ease progress tracking: