This first statement of yours read to me as a generalization for all snakes. You said "In all cases..." which is why I commented, because that absolute regarding "all cases" is not correct.
Yes, I know, and that's why I said "...but apparently the boids like to produce all females." It was late for me, I was tired (11 hour shift at work plus bottle feeding 10 day old kittens) and forgot to include "and the pythons are likely to do the same" as they're both 'ancient' snakes versus the new kids on the scene who make males.