>I guess the BSD folks will be thilled to hear that they did build the GNU system too
They should be! If they managed to build a completely free operating system succesfully they would have no reason not to be thrilled at the completion or success of such a monumental task.
I don't think they will call it GNU though. The BSD folks also go a long way back when they set out to write a free operating system. But the set of values they wanted to achieve are different than those of the GNU project.
There is no reason, historically or otherwise, to call their operating systems "GNU", although I think most of the various forks do retain the name "BSD" in their project name.
That said, I'm sure I run various bits and pieces of BSD software on my GNU/Linux system, since, as you write, "[the] license is right."