When version 2 is out, you will have the option to upgrade for a fee or to continue to use version 1 for free for as long as you like.
From the pricing page:
"Enjoy the benefits of our lifetime license and get access to all features and upcoming updates with a one-off payment"
A new term such as 'All version [n] updates included' (or something less clunky) needs to be found. At least one could Google it and understand the proposition, if its meaning was not clear - but 'lifetime license' is massively deceptive.
[1] https://reddit.com/r/4kdownloadapps/comments/1hbmdpn/really_...