FEED spoiler party!

Weeeellll.... just as a minor and possibly not relevant point, historically major depopulation events are followed by a significant loss of freedom, especially for women - the focus suddenly being on rebuilding the population quickly. The most notable instance of this which I can think of is the Mongol invasion of Japan: prior tot hat time, women had almost achieved political parity with men, but afterwards those privileges all but vanished.

However, this may not be relevant as:
1) We're already at a technological point such that a lower population might be good for the economy; there's no real impetus to rebuild to pre-Rising levels.
2) Modern Western culture isn't feudal Japanese, nor in fact feudal anyone culture, so reactions are notably different.
3) Kellis-Amberlee isn't a Mongol invasion; in fact it acts differently from just about every other threat humanity has encountered.

So, net meaning is that things like gay marriage aren't fait accompli after a big disaster.

Of course, it's your world and if you say that in the face of the living dead people stop arguing about whether or not gays should marry and how many eyes god has, then people stop arguing about such petty things.

Of course, realistically major social change takes 2-3 generations - long enough for the people who remember that way things used to be to have died off. We tend to get impatient and forget this.