So the conclusion of the comment-article cited in the parent of your comment is false?
"According to the current phylogeny, FCS appeared independently six times in the Betacoronavirus lineages, demonstrating that FCS insertion is compatible with natural evolution (2, 7, 8).
[...]
7. Wu Y, Zhao S. Furin cleavage sites naturally occur in coronaviruses. Stem Cell Res (2021) 50:102115. doi: 10.1016/j.scr.2020.102115"
"According to the current phylogeny, FCS appeared independently six times in the Betacoronavirus lineages, demonstrating that FCS insertion is compatible with natural evolution (2, 7, 8). [...] 7. Wu Y, Zhao S. Furin cleavage sites naturally occur in coronaviruses. Stem Cell Res (2021) 50:102115. doi: 10.1016/j.scr.2020.102115"