Even in the matches I do, I will take advantage of every bit of information I have in order to referee the game more effectively.
Here's an example from my personal experience. In August, I officiated a match with a U17 boys team. I then officiated them in early October. In the August game, I cautioned their central defender in the first 90 seconds for a reckless challenge (was considering going straight red for a moment). When I officiated this team in October, I knew this player was fast and aggressive. The other team had a fast center forward, so I knew the possibility existed for a late challenge because of the defender's aggressiveness and the attacker's quickness.
So in the October match, the defender gets a foot in late but doesn't make contact. I swing by him and remind him to watch coming in late. Not two minutes later, he clips the center forward on a late challenge.
I caution the defender, and two of his teammates yell at him, "C'mon, he just told you!"
I see nothing wrong at all knowing who the key playmakers are, whether they like to attack down the wings or the middle, etc. If I have that information and it helps me be where I need to be and what I may expect, I'll use it. I don't think it's being biased at all. It's being prepared.