Hi!
It's Kuba from Nozbe Team. I get your point. It might be a bit confusing, so let me make these things clear.
A new version Nozbe, currently called “Nozbe 4”, will be, indeed, focused on teams. But we're not ignoring individual users; it's a thing of focus rather than cutting off. If something is useful both for solo and team accounts, will be brought to all; if it's useful only to teams, it shouldn't burden individual users.
We will not force users to switch to the new Nozbe after presenting solo accounts in “Nozbe 4”. We're going to support the current Nozbe (Nozbe 3.X) for a reasonable amount of time (counted in years.) It's a mature and stable app, and, as Robby wrote, it won't be changed drastically (but some new features are on their way!)
You can feel encouraged to use Nozbe and, when solo accounts will appear in “Nozbe 4”, decide what to do next.
For GTD-related inspiration, check out this article from our user about how he implemented GTD in Nozbe.
Let me know if you have any questions!