Maybe that's the only time of the year that you can enjoy the sun and warm temperatures (and hopefully not anywhere near to oven baking temperatures like we had last year) and you wouldn't spend much time at the PC anyway?

Or you shouldn't at least

unlike the vanilla cities skylines, real world actually has day/night cycle in summer to as well as bad weather.
but anyway, release in october seems to me the most likely scenario going by the csl1 timeline and 7 month period from the announcement phase to the final release.
Cities skylines announcement trailer: Aug 2014
Cities skylines release: March 2015
Csl 2 announcement trailer: March 2023
Csl 2 release: October 2023
this calculation ofcourse doesn't account for long summernholidays at CO, so i'm willing to bet the release to be postponed due to that for another month or two. So November/December seem to be quite likely as well.