It should work that way, but in practice it sometimes does not.Will an ameraucana cross always have a muff/beard when crossed to a clean faced chicken?
An Ameraucana is supposed to have two copies of the muff/beard gene, so every chick gets one, so every chick shows muff/beard.
Many chickens sold as "Americanas" (wrong spelling) and even as "Ameraucanas" (correct spelling) do not have all the traits that an Ameraucana is supposed to have. So a chicken with the right name (Ameraucana) and the right appearance (including muff/beard) may have just one copy of the muff beard gene, which would mean half of their chicks get it and the other half do not.