Hey, Alexandre.  Had I done that, my comment would have been disconnected from my actual experience: I frequently encounter the phrase "open source alternative to" and only rarely encounter the phrase "free software alternative to".  I was talking about a phrase that others use that I decline to use, not a phrase of my choosing that I either do or don't use.

(I consider the terms synonymous anyway, and have ever since the term "open source" was coined for this usage, but that's a much more complex discussion of course.  https://opensource.org/faq#free-software has some of the background on why one might choose this interpretation.)