So if you know them, and you solved the problem ignoring them, why make this non issue am issue?
You may justify the request with the desire of helping the ”poor victims”, but I see not victims, but rather you trying to play police, but not making yourself the effort, instead forcing others to waste their time.
Previous comments provided fair solutions. And is simple, make your own challenges if you hate surprises. And who really want to see their real rank, can scroll the games and see what ranks they defeated. For a second I had the idea that premium account could have the option to see a parallel
ranking were unranked games are ranked too. But this is stupid, is just a waste of effort for an non issue.
Or we can assume that who chose to play against a players with no rank, is a sandbagger, since the new player obviously may be a beginner. And a sandbagged sandbagger will be really upset, and try to police the other pathetic sandbagger 
Sandbagging was discussed extensively and one of my answers is here, and I have nothing more to say about the subject.
But I have some other aspect to touch. Is about the person who does this. Why is he choosing to waste time with weaker opponents? Is there any satisfaction win winning when the opponents moves are lame? It is obvious that the person have some mental issues. ( similar to someone using bots to win the games)
I have a good friend with a similar problem. He is passionate, study a lot, kibitz a lot, even sponsors and promotes Go, but never plays. I confronted him, mocking him that he is afraid to lose, but he shy ed away deferring an answer. I let him be, did not insisted too much, but few times somehow we played some games, and I was almost to lose, even I had decades of competitive play.
accurate ranking is more problematic with face to face competitions, especially international. And there you pay money and waste time on travel. online you have several servers to choose from and a lot of players. you can make teams, organize competitions with players you know. so just asking for more accuracy for casual games is asking too much.
And I hope that you will see that is a non issue. I went at lengths above explaining.
And a newbie hard to get games? Bots are available, you get a rank in no time.Or you can chat and find partners and teachers, or just accept challenges til you find one with no lower rank restriction.
Predators? Rather poor souls with clear mental problems with nothing better to do. If you really think that they are such beasts that deserves punished, than you can lower at their level and accept their games and use AI to beat them. Or play really really bad, so cancel any feeling of winning. I fall sometimes in this stupid revenge when somebody with rank similar to mine plays absolute junk, with the hope that I make a mistake. Than, I serve the same medicine and play every single atari in their territory. But is a plain stupidity from my part. .