To the best of my knowledge there is nothing special about these reviews; it is just that they are more rare and thus not that often available (plus the scarcity creates additional demand).
As said in a comment if you want to perform those reviews frequently you need to check often, or have a script that does it for you.
For example https://stackapps.com/questions/6517/review-queue-desktop-notification-script could help.
It is not for late answers specifically though.
In addition, at some point there was a flood of such reviews as the criteria were changed. But due to daily limits this did not contribute that much on an individual basis.