I meant to post about this earlier, but I forgot...
I finally did watch the video for real some time ago, and it mentions that, yes, the blue sky process is important. However, they add, that's only the first step; there also needs to be an audience. One should also have a mediator, the person who sets up the brainstorm session because everyone needs to work in one direction. No one person can or should work on a project alone.
Also, it sounds like the issue of constraint does not matter at first, but will matter somewhat later on. However, it seems as though the blue sky process here at this forum is all that matters. He said to take a moment to forget about constraints, the key word being "take a moment", as in "at a later time, because it will eventually happen".