I think you're right about words describing styles being flexible but wrong given the amount of flexibility you expect and the examples you've given. Minimalism, in every example I can think of, has a context. What you've described is a minimalist percussion exhibition and a minimalist recording. If you asked some people to describe those two things I expect you would get some similar thoughts. The focus is on the recording and not the location of the recording. The studio would not be a focus on whether the recording was or was not minimalist.

But there are assumptions, context, about lifestyle minimalism that the minimalism supports some goal to minimize consumption with an eye toward "the things we own end up owning us" and to keep their footprint small. The gp notes that the subject of the article has not actually done that, he's just pushed consumption off onto other people and businesses. An example you asked for of someone who lives minimalistically is a myth I heard as a kid about people who could fit everything into their VW Bug and be on their way.

I guess I don't think you're wrong so much as right but the gp's assumptions are common and more accurate to how minimalism is usually thought about.