Seeing competitors name in match history: sometimes yes and sometimes no

I have noticed that I don't always have all the names of the people that fought in my previous matches. Usually happens after a patch. What is the correct behavior, if anyone knows? Are you supposed to be able to see their names or not? It would be cool to go back and look at those you faced and those that helped. You could friend them later or take notes if your client crashes. I just want to know if I should be looking to fix it or do they not want you to know later.