"There was a major change in the handling of layer 2 vlans recently. You may need to convert from old style vlans to the ELS system as part of your upgrade process."
This statement is inaccurate. SW does NOT change CLI style between old [non-ELS] and newer ELS. This is determined 100% by hardware platform. Legacy EX use non-ELS always. Newer EX use ELS always. You can not take an EX product and move from format to the other via SW.
FYI