Not quite. Android was likely never intended to be open source originally, and was only opened after Google bought them. Easiest way to get around any licensing issues is to (properly) re-implement from the ground up.

Most closed mobile OSes being the insular things that they are, don't bother to implement any existing standards and will do all sorts of nasty, hacky things that the end user is never supposed to see. I suspect that Android's intended business model would have included a patched kernel ready to go, instead of Google finding themselves trying to integrate everything into the upstream kernel.

All of Maemo's closed components are in the upper-levels, and there's no reason they couldn't be replaced (and with luck, there won't be any closed components like them in the base distribution.) This is a licensing issue to be taken up with Nokia, Android's issue (as described in the post you quoted) is a technical fault as a result of (likely) closed-source design philosophies being suddenly made open.