I would assume like my own game that the plan would be to upgrade to the full official version after Gen Con for game groups. I can't see LW wanting to support two different versions of PF2 and with the sweeping changes Paizo is talking about. A realistic view would be that if you want to continue using ONLY the playtest rules after GenCon that you will need to print your character and go to pen and paper.
For me personally I would be fine if LW just deleted/removed all my characters so that I can start fresh for PF2!
I have zero use for the 30+ test characters I built during the playtest...