Ok OP, first, you cannot use a blue post from the Classic Dev team to justify why something in retail is the way it is. Retail and Classic are two different games.
Next, 1.12 AV was most likely used in Classic because the code base for AV 1.12 was closer to the current code base running in classic so it made logical sense. AV 1.15 or higher code might not have been as compatible with the 1.13 code running in classic right now.
This same logic most likely applies to retail as well, the 1.15 AV code might have been the earliest version of AV they could make work properly with the current code base running in retail.
Trust me, there are no “Let’s screw the playbase” things going on here, its all about how much coding effort is required to make something work.
It doesnt really matter which version they went with because xp gains is pretty much trumping it all. Thats whats driving participation so in a sense that was the most important decision made.
Uncertain how that would factor into why they did not use 1.12 AV. If anything it shows the development time wasted on it (15th anniversary) even more egregious.
Honestly, your guess is as good as mine. Classic would’ve ate it up for sure, yet it was put in retail. Feels tone deaf, and a good way to dissatisfy both communities.
Your counterpoint is flawed by the assumption that I care if the games are on the same sub. Separate them if you like, I have no interest in Classic. It’d be pretty hilarious how quickly your population would plummet if that happened, though.
And you got your $15/month worth of content. You cannot play Classic and Retail at the exact same time if using the same WoW Account (not Blizzard account). So with that barrier in mind, both parties cannot get more than $15/month worth of content because you cannot play both games in parallel.