This is an incredibly simplistic take. Yes, if all the men die and none of the women are pregnant and they don’t survive until some of the children reach sexual maturity (why would there be no children before the men went out to hunt?) then yes, the tribe would die. Doubtless small groups died out this way on occasion, among others. None of that has any bearing on fewer men being needed to keep a population growing because it does, in fact, take only two to tango, and both men and women can tango with multiple partners.