By calling Jesus "Emmanuel," Matthew was equating Jesus with the Messianic figure mentioned in Isaiah 7:14 -- "Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel" (KJV). It was an exceptional case, used to "prove" Jesus's claim to be the Messiah, and should not be considered indicative of contemporary onomastic practices.

Emmanuel is a description or title, much like Messiah or Christ. His name was just Yeshua.