The timing is no coincidence, as the MDN docs team was part of those layoffs. It would be a cruel act to layoff the MDN team while also trying to improve the perception of MDN's value.
The timing is almost certainly related, but I interpret it as the community trying to voice how important MDN is to everyone in an effort to convince Mozilla that it deserves priority, or at least doesn't deserve further cuts.
Having said that, I find the timing of this site very suspicious, as if it were part of a secret PR campaign for improving Mozilla public image, after the recents layoffs.