If I'm right the reason it's not being analysed or investigated is that from a scientific perspective it's just not an interesting question, rather than for a deeper ideological reason as suggested in this article.
I drew the conclusion that this furin cleavage site theory wasn't actually convincing after a few days of wading through scientific literature, but as a non-expert I was pretty disappointed that there wasn't more accessible analysis of well-written arguments as presented in the article that would put it into a more objective perspective. It would have been great if that scientist they quote would have provided a more detailed rebuttal.
The problem is it actually isn't the job of scientists to dispel wrong or inaccurate information for the most part. They do detailed esoteric studies and write them up for specialists. It's nobody's job to rebut bad arguments, and that's the problem.