That's interesting. I hadn't expected that.Also they are all without crests
Either the hens are carrying the gene for no crest and each chick happened to inherit that, or else the chicks do have the crest gene but their crests are not big enough to see. I don't know how common that is, but I have seen a few photos of Legbar-mix chickens that had crests so tiny they were hard to notice, so that might be one explanation.