Where does it say that you have to migrate to v8? There's nothing on that page that says you can't continue using your old "lifetime" license for, well, a lifetime.

On the other hand, if you want to upgrade, I think it's reasonable to expect that you only get the new updated version if you pay whatever they decide to charge for. You, of course, are entitled to vote with your wallet if you don't think the price is fair.

Am I missing anything?

ps: no relationship with AgileBits, other than being a customer since the days of "lifetime" licenses, and now a happy subscriber of their family plan.