Google AdSense is experiencing "temporary delays during the coronavirus (COVID-19) pandemic," which means Google is unable to review certain sites at this time. Google is displaying this message in the "Site Review" section of the AdSense console for some sites.

Here is a screenshot of this review from Sunny Ujjawal on Twitter:

I'm not sure how widespread this problem is, if it affects 100% editors requesting site revisions or just a certain percentage.

Discussion forum on Twitter.