In addition to standard upgrade requirements, Widebody Command Upgrade requirements are:
a) 6500 hrs
b) 2000 hrs are flown on aircraft in excess of 100,000kg (A321 is about 93,000kg mtow)
c) 1000 hrs and 2 years experience on the fleet for which the command upgrade will take place
So an A320 CA would have to go back to being a WB FO before becoming a WB CA?