I was asking for a link to confirmation that the new version will be a free update for existing customers. I'm not sure where you heard that from. Though I now see it on Twitter. Thanks.
Not sure anyone actually knows apart from Twitter and Tapbots.
Technically they can class Tweetbot 2.0 as a "new" app and start afresh with the tokens. This is what a developer did with an Android Twitter Client a few months back.