Given that furin cleavage sites have been found naturally occurring on other, earlier in the phylogenetic tree of coronaviruses, viruses than SARS-CoV2, the natural assumption is that such a site is not only possible to develop, but likely to develop, in wild sarbecoviruses. Shifting the goalposts in no way whatsoever implies or allows the idea that this furin cleavage site tack of yours is evidence of anything but natural selection.