The problem with it is that one can invent a scenario that never happened and asked for an explanation and similar such plausible explanations can be proffered for it, but there's really no way to actually verify and test them.
It can just as easily be explained with “It is a simple fluke that will repeat itself in another 70 years.”.
https://www.livescience.com/19311-famine-male-births-sex-rat...
It's observing an event, formulating an explanation for it that sounds plausible enough, but the explanation is unfalsifiable, and a number of other explanations that are just as plausible and unfalsifiable can be proffered.
It doesn't. In a species with 50/50 split between male and female, the number of males is almost irrelevant to population growth. Take rabbits. If you kill at birth 90% of the males, the population growth won't slow as the limit is the number of babies per-female. The 10% of males that survive simply father more kids via more females. Males can do that. Females cannot. Going one step further, killing all those males increases the resources available to the females. Ironically, culling those males can cause a population to grow faster than if they lived.
The split between male and female isn't relevant to this. Unless the males are needed to raise the children, the number of males is irrelevant to population growth.
But the average benefit of having a son remains equal to the average benefit of having a daughter; that's why the ratio stays at 50/50.
Then it can get very extreme. Fatalities can occur.
Death by snu-snu!
I think the presence discrepancy is reasonably well accepted.
https://www.livescience.com/19311-famine-male-births-sex-rat...
https://www.livescience.com/19311-famine-male-births-sex-rat...
Note that typically older males mate with (much) younger females: It's no coincidence, that she is that much younger than her male counter parts: She is angry about her mating partners that they have stopped mating (with her). Older females have offspring. The old alpha male, which is dead, has a lot of offspring. The external life conditions just became too harsh, this is not a happy setup. There are 2 strategies, but one is to react on external circumstances (stop procreating), instead of blindly going ahead and having to stem the bill later (starving babies). Apes are intelligent enough for the first, but there are furious women now (including "her").
That much is known.
We can also speculate that if daughters are now receiving more investment as children, they are better positioned to go higher in society as they become adults. A general shift in political power, throughout social species, should be expected, as the climate crisis threatens more and more species with extinction.
This might extent to even those species in zoos, as their population usually is not allowed to expand.