While I’m no staff member (if you are one, please feel free to add your thoughts!), I can safely say, no.
It could be exploited, to convert helpful answers into comments.
By converting answers into comments based on who answered, just because they could convert it, etc.
If there is a need for it, an expert+ will convert it. If they don’t, it would be easier for someone to contact one rather than risk trolls and stuff.