"Alternative Technology" seems problematic to me, and I think "Free Technology" would make more sense since what this movement is aiming for is freedom. I will explain further as to why I think this way.
The word "alternative" presumes that a certain software/technology that is free is just there to serve as a similarity to this proprietary/non-free technology("YouTube alternative", "YouTube clone", any kind of "clones"), and in effect assumes that technology that is free should coexist with technology that doesn't respect users' freedom, rather than serve as a unique replacement.
Also, there is already an "Alternative Technology" that exists(though it has a different meaning).
I honestly think "Free-Tech" sounds better than "Alt-Tech". "Alt-Tech" just reminds me of "Alt-Right". We can refer to ourselves as the "Free-Tech Movement".
What do you goats think?