I guess the buyer's guide is incorrect, then, as they say Don't Buy - Updates soon, and have said so for over 1 month now. 10 months between updates would not even be until June.
Buyer's guide goes back through ALL models of machine, disregarding changes that could affect upgrade cycles like a change in chip provider/underlying architecture. The argument was made that Intel iMacs have so far been updated every 10 months or so and it is a valid argument.