I believe this information this changed.

It's possible that the plan for going from TOKEN->SuperNET on the Nxt AE is changing and that it will now happen via a share swap. TOKEN holders will have to send their asset to an address and only then will they receive SuperNET. (This is to prevent confusion/scams in terms of TOKEN.) In this case TOKEN won't lose its value but will become extinct as it is all sent to Genesis (This is the way to destroy assets/Nxt in the Nxt system.)

Best to wait for James to confirm.