The liberals will take any opportunity to attempt to shift the focus from the central part of the story...Jesus, and shift it to something else...in this case Zororanstrianism.
You're right, it's just new spin because Jesse Jackson's line about Jesus being homeless didn't catch on.
This does not prove that the "wise men" were Zoroasterian. The Greek word magoi is used in only one other instance in the Bible, where it is not translated as "wise man" but as "sorcerer". See Acts 13:6-8. This sorcerer in Acts is also called a false prophet and a Jew. His names are Barjesus (son of Jesus) and Elymas which translates as "wise man".
By this example from the Bible, it is entirely possible that the "wise men" could have been Jews.