In the wake of what was innocently called a "rebalancing of old event buildings" (and there is a very long list of them, and not all of them are even that old), my population dropped from +700 to a horrific minus of 1200. I am at the start of Dragons&Sorcerers, and all my residences but one are fully upgraded and further upgrading in this new chapter comes fairly late, and then, residences change their orientation again, and space is as usual a massive headache.
I put time and money into events/quests, in order to get the event buildings, which give a decent permanent increase in population and have done so, since I started playing Elevenar in spring 2015 - it is a real help with achieving growth a little bit faster in the game.
Not everybody does it that way, but substantial amounts of players do, and I think, it is really outrageous, that such players have all been seriously disadvantaged by this game update, who have spent time and often/usually extra money to get the right population giving event building, by all of a sudden robbing them of serious amounts of population.
The Elvenar developers, who have come up with this, for however good their reasons might have been on a game operative level, have made unfortunately really easy with the money of many players that way - it does feel very wrong and not a credit to the game at all, never mind any respect you might (and should) have for the people supporting the game and helping it grow.
To read on this forum, that there was an outcry on Beta against this change and it was not heeded, makes this even worse.
I would strongly advocate, that you give people back their population they have lost.