Every AAA publisher wants their game to be the mass audience hit, and releasing near Christmas is just a period of more mass consumer spending.
I think for AAA action games that aren't already very established franchises...it is indeed a stupid period to release, because you will likely get swallowed up by other franchises. Mafia 3 and Titanfall 2 are pretty screwed, which sucks especially for Respawn because they made a great game, and I'm going to bet they didn't choose their date.
Gears of War 4 is a special use-case, in that it's an established franchise that will sell well enough, but like Forza is a tool for Microsoft to also move their hardware and ecosystem.
Other AAA games like Dishonored 2 I think are fine, because it's a slower paced more stealth-driven experience that will find an alternative crowd, and it got some real hype at E3. FF15 is a JRPG from a very venerated franchise, the curiosity of this long awaited game will be higher than the disappointment of the FF13 games, and it has a built-in audience of people that like that style/vibe of a game. Civ 6 hits a completely different audience of people than any of these other games, including people that barely even play games, and even people of older average age.
Be an already big game that commands an audience, or be a game that grabs a different audience than blockbuster action games.