Some inaccuracies in the timeline. Solaris 2 (the sysv one; the BSD SunOS 4 was after-the-fact renamed to Solaris 1) didn't ship until 1993, not the 80s. Also he says that gcc's support for 68k was important but Solaris never ran on that platform -- Sun made the switch from 68k->SPARC a few years before the BSD->sysv change.

The wider point is correct, but it isn't limited to just Sun. The decision for many UNIX vendors to charge extra for the C compiler was a big reason that gcc caught needed momentum. If that hadn't happened the whole free *nix history might have been very different.