I don't know about that, but my neighbor is from the Phillipines and she raised chickens over there. She said the pointy eggs are roosters and the round eggs are hens. I haven't tested this myself , but her husband said he tested it and so far with their chickens, she has been right.
Egg shape is a factor of breed and individual hen. It does not determine gender. Nor does temp during incubation. These are "old wives tales."