Aion and Tera both had something like that, even though it was more limited in Aion and in Tera it was only lvl 20. Tera is also doing this again with the new class added, you progress faster cause you end up starting at 45 or some shit. Think DK in wow, where you'd start at 55 or whatever it was and acquire bunch of skills quickly.
I think being able to see how your class plays later on would be good, but at the same time I don't think most people care. They just pick something that "looks" good then play it badly for a while and quit when they get bored, not because the class doesn't fit them. Most people who care about classes will tend to get into open beta and play most classes to mid level to get a feel and do research on their choices anyway. I'd personally like it, but I see why they don't bother wasting ressources on it.
