@Xerosaur
While well presented, the flaw in your argument presupposes Inno's motives are pure. I don't believe they are.
I believe Inno knew from the get go what the reaction would be, hence the A/B rollout (not test). MTG/Inno couldn't care less about free or long time players leaving, they generate little to no revenue compared to new players.
Who's going to spend more? The new player looking to build their cities rapidly or the legacy player sitting in the last age waiting for the next one? Who also generates the most complaints? The new player who doesn't know any better or the legacy players who remember the way things used to be?
At some point, this change (let's call it the Great Reset), will reach equilibrium. Those who will quit will have quit, eventually replaced by new players who know nothing else. Once that point is reached (zero sum or net positive revenue for MTG/Inno), they will proceed to the B group roll out, where they will just rinse and repeat. Flushing the legacy players in favor of the Noobs who know nothing else.
Honestly, other than the temporary PR hit which has now been highly suppressed here on the forums, I see no downside for MTG/Inno, only upside. With the loss of last age players at the top. Top spots are opening up, which means players who had no chance before of getting to the top now can, if they spend enough, of course. This also relieves the pressure of having to quickly develop new ages that new players won't get close to for years.
It's quite a brilliant strategy in a Machiavellian kind of way. I could be wrong of course, but time will tell.
I think this "test" is producing exactly the results Inno wants. The only question is how long the A part of the "test" will last before the legacy players who quit or stop spending are replaced by new players who know no better. Once that happens, Inno will declare the "test" a glorious success then roll out ads to the rest of the players. If a Great Reset in the player base were my goal, this would certainly be a great way to achieve it.