Impact of updates on retention

It does not matter if WoW has around 12 million subscribers. What matters is how many users connect monthly to the game. As shown in my paper, half of the 40% of players who stop playing the game for more than 6 months never freeze their subscription (ie they keep paying but never login). Since they pay, some would consider them active.

Who are those inactive people? It is hard to guess. Therefore, let's flip the question: what are the patterns of (in)activity for various player demographics? By player demographics, I do not mean achievers, explorers, etc. from Bartle or any psychologically-based categorization of players. I would rather focus on the extent to which people play in relation to the game updates, in WoW raiding more particularly.

Category	Ratio of total player pop. (estimate)	Behavior
Pro gamers	<0.05%	Intensive play on PTR right before update deliveries. After four to six weeks, all heroic-mode bosses have been downed by their guild (with eventually some world firsts). Then they stop until the next update.
Dedicated raiders	<10%	This category could be called hardcore, but hardcore is an umbrella term that does not mean much. Those players eventually try out new bosses on PTR. Server-firsts are their goal. They raid three to seven times a week, and spend a considerable time looking for strategies or theorycraft data. Once active guild members have received most of the top-ilevel gear, the raiding activity decreases, and people log in less often. They take a break after 3 to 6 months depending on how dedicated and skilled their guild members are.
Amateur Raiders	>90%	Continuous raiding. They take their time to raid (once to three times a week), and their raids look more like spontaneous pick-up groups than organized expert guilds. Every body complains about the few who really do not pay enough attention and supposedly cause the wipes. Only patient officers spend time reading strategy guides and coach their guild members. These players have content at least until the next update.

Since amateur raiders make up the bulk of the WoW player population, this slow release cycle does not apparently harm the WoW player base so much. However, it seems to me that a diverse range of players (dedicated + amateur, for instance) gives more stability to the player base. Therefore, it might be worth it trying to retain dedicated raiders longer (say, a year's worth of content for each biyearly expansion).
Below, a totally fake graph to show how all this would look like.

Limitations

These qualitative categories may not be the most accurate, but they reflect trends observable in the game, in the few informal player interviews I conducted, and in quantitative studies.

The speed of updates may affect the retention rate of particular player demographics. Blizzard is known for taking its time to release well-polished updates every other year. SOE, on the other hand, has been releasing extensions for EverQuest three times faster: every 8 months on average. What does that mean for retention?

Each player category is affected differently by the gameplay (PvP vs PvE vs PvPvE vs sandbox vs ...). In this article I focused on PvE, but maintaining a top position in the PvP ladder on one's server takes dedication. Another example: the number of EVE Online players has been increasing steadily up to 350k subscriptions, possibly because fans of this kind of gameplay have to be very dedicated. Can these players be considered loyal, though?