No. Open source is the same as free software. It is a marketing term for free software, that defines the same concept in more practical terms. If you actually read the article you linked, you would have known that.
There are broadly two camps: Camp 1 who advocate for free software & free software alone, and Camp 2 who advocate for "open source" being an all-encompassing umbrella term for a few things, including free software. Those in Camp 1 are typically not supportive of the goals of those in Camp 2. Those in Camp 2 do often try and equivocate the two terms.
It really is the whole point of it, define more clearly what criteria must be fulfilled for software to be considered free software.
Is this a typo?
[0]: https://www.gnu.org/bulletins/bull1.txt
[1]: https://news.slashdot.org/comments.pl?sid=1129863&cid=268758...