web.dev managed focus and WCAG

The Lighthouse accessibility report lists the following between the items
to be checked manually:

   - The user's focus is directed to new content added to the page (
   https://web.dev/managed-focus/ )

While the meaning and the importance of this item are clear to me, I'm not
sure which WCAG 2.1 criterion, if any, could be met by following this
suggestion. web.dev gives no links, and while the other items in the list
can be easily linked to a WCAG 2.1 criterion, I have doubts on this one.

Can someone help? Thanks in advance :)

-- 
Mattia Gentilini
https://www.antreem.com/