I've had plenty of leads come via whois for my BB names who had no idea about BB or who had visited the BB landing page by type-in.
I was also in BB's now defunct affiliate programs, and I had quite a few sales that originated from my type-in traffic and not from visits to their site. So I have some hard data and direct knowledge of the level of sales via type-in. They'll never admit to this of course.
Good question. I previously gave notice that I was taking my names down, and my intention was to build an Efty-like system, but other commitments have gotten in way (domains are only a side-gig for me). I've again given them notice that I'm taking my name's away recently, and this time will follow through. Being honest moving 1K names to anywhere else isn't a trivial task.
As much as I love your insight in brandables I have to disagree. I've sold plenty of these names outside the brandable marketplaces, and I think good 6L's will continue to be the brandable name of choice for many startups and rebrands.