Because per se it does not prove the claim of bioengineering.
You are of course more likely correct about the alignment issue, I can't find my source now, and the above is probably much stronger evidence. For the alignment you'd have to be a virologist, probably one specializing in coronaviruses, to be able to really judge this. Of course a whole bunch of biologists have shifted their focus to coronaviruses in the last year and a half.
So still nothing to point out to bioengineering in my opinion.