The comic books about Zayne and co. (which I do read and enjoy) are based on the games, which are in turn based on the earlier Tales of the Jedi comic books. That's the way it should be IMHO.
Sure, you can have references to Zayne and his companions in the games, but you can't put the characters in a game, since that would interfere with the writers (of the comic books) creative control over the plot. Doing so is poison to good storytelling in my experience.
Indeed, it would have been easy to write lots and lots of stories about the early days of Revan, exile, Bastila, Malak, Nihilus, Sion, Kreia, Visas, Mical, Canderous... you get the picture. But they didn't do that. They wrote all new characters instead, and so we have Zayne as the protagonist instead of Revan/exile, Jarael as potential love interest instead of Bastila/Carth/whomever, Rohlan as the token Mandalorian instead of Canderous, Camber as the grumpy old dude instead of Jolee/Kreia, etc. That's because the plot is about the characters, and if you put the same characters in too many stories, then you lose the option to let powerful events happen in their lives, since they must be around the way we know them for the stories that are already established at some other point in time (note: this is also the reason why I have low or no expections for the proposed Star Trek movie about young Kirk and Spock).
This means we can have cameos by Carth, Saul Karath, and possibly Malak and Revan in the KotOr comic books during a time when it is already established that significant events in their lives took place and which can therefore be explored in more detail than we've seen before - nothing changes, we just see more detail, and so the characters are who they must be. For example, I would would consider it disastrous to have Bastila in the comic book, because she needs to be fairly naive and inexperienced for the plot of KotOR1, which a story where she faces significant choices at an earlier point in her life would interfere with.
For Zayne and company: read the comic books.
For Revan and exile: play the games.