I sure hope they doDepending upon the cause for their shortness, they may very well grow back normal. It is not uncommon to pull such feathers in show birds. Sometimes even off color feathers regrow the proper color.
If he is just a cockerel, my gut says that his mature sickle feathers will be longer. Hopefully he takes after his father.
He turned a year In September, so once he molts it'll be his first molt.Joe how old is he? It’s taken my standard size cockerel a long time to grow long feathers. His were short too.