Honestly infrequent updates would not be a problem if they were designed to last longer than they are and have a place in future content, rather than being mostly throw-away by the time the next cycle rolls in I mean in regards to WoW when it was at it's high point, wotlk patches were 5+ months inbetween, yet there was enough to do inbetween that kept me interested.
You'd have daily hubs that;d change over time, a variety of dungeons that kept me interested (especially in regards to the gearing process; heroic dungeon drops were actually relevant for intro end game, rather than being outdone by justice point gear, or our current equivalent of eso tomes)... Here, ever since 2.5, I'd be done with the novelty of the content as early as 5 days (or 2 days in the case of 3.1).
Mind you WoW had daily lock outs for dungeon and weekly lock outs for currency. Between getting a heroic dungeon drop, getting mats for an engineer to craft my Nesingwary 4000 as my entry level raid weapon, the gearing process kept me a lot more interested than having to rely on weekly tomestones to get my gear...which honestly could be capped in 2-4 days if I was farming EX primals or both 60/ex roulettes. As new raids were introduced, the previous tier raid gear was still relevant (and to a lesser extent, required for number checks) to the current one, and updates to their "tomestone" wouild not completely invalidate the previous tier of raids. I was still using Naxxramas pieces going into Ulduar; there was no better option from the tomestone vendors, but it's not as I needed a full set of naxxramas to be able to perform in ulduar, not unless it was hard mode. It wasn't until Cataclysm they started to decline it by having less content to do at end game (since most of the design of the expansion was redoing the old world), likewise with MoP and WoD is an entire mess of it's own.