She wasn't meaning to be sassy. However, if you look in the coven forum thread at the top the second post does say that the feature was disabled back in 2010.
As for determining what the most active covens are on site currently: look into each of the covens. On the Groups page, you can scroll to the bottom to see the list of "inactive" covens. With the reminaing covens: By going to their individual pages, you can see who the Priest/ess, council and members are. First, check to see when the Priest/ess last logged in. Some groups lack active HPs and it makes for inactive covens. You can send messages to the HPs, the counciul and members in order to "feel" out how active a coven is before you join, and to see whether or not it would be a good fit.
Best of luck.