I think it isn't because it does not assign 'yellow stars' to users for being good boys, the sort order always was open to interpretation, if this one is less gameable than the previous one that would seem to be an improvement to me.

The problem I perceive is that average score does not say much about a specific comment being non-productive, so someone with a high average score could toss in some complete junk and get it sorted to the top in spite of better comments by average under producers further below.

I'd say that if it remains below the detection threshold it might be a net plus, if too many of such instances appear it might be a loss.