But how open is it to other open source OS kernel besides Linux? For example, would they send a pre-release boards to FreeBSD or OpenBSD "kernel hackers" if there was interest?

Though it may not be intentional the article seems to have a strong Linux bias.

I want more hardware like this and I always use open source software, but I may not necessarily choose to run Linux. Nothing against it, simply personal preference. I would like to see hardware that can run a variety of kernels.