Originally Posted by
Cap'n Benj
I maybe incorrect but I believe that was one of the (many) reasons I binned the card off after the mega bonus period ended.
Me too, but I think that the rules are slightly different under the new scheme. For a start the old voucher only allowed travel in Y

whereas the new one allows J.
I think...
To the OP, you only need Avios availability in the class you are upgrading to, not from as well.