Do not fear, the original (and still the best) Aggregator sites are here to stay!
Hat tip to reader Simon M. suggesting that I subscribe to the RSS feed for each announcement Geeklist. It worked perfectly!
I no longer need someone to email me the list each month. Thank you Simon!!!
Leaders are calculated based on unique entries each month. A unique entry is a single game (or one of its expansions) by a single user in a single month. This eliminates multiple entries for a game by the same user during a month (an acceptable practice, but one that dilutes the stats).
As of February 2021 (applied retroactively), expansions are counted has having played the base game.