Yes, he's talking about a disagreement there with the open source movement. But the overall thrust of the article is that FS and OS are the same thing, overall, but lead people to different conclusions. He explicitly addresses the misconception that people think that only copyleft is free:

    Another misunderstanding of “open source” is the idea 
    that it means “not using the GNU GPL.” This tends to  
    accompany another misunderstanding that “free software” 
    means “GPL-covered software.” These are both mistaken, 
    since the GNU GPL qualifies as an open source license 
    and most of the open source licenses qualify as free 
    software licenses. There are many free software 
    licenses aside from the GNU GPL.

And that's all I want to get across. rms isn't as loony as people who want to disagree with him make him out to be.