Well i'm going to play devil's advocate a little.
This may be a scam, but why assume it is just because you have to wait?
The probationary period is instituted in a lot of places I've been to, talked about, or heard of. It can be a valuable tool for the instructor to determine whether you're going to act like a black belt once you test for it, or, in my opinion, act like an ungrateful brat and walk out the door. part of beinga black belt involves loyalty. part of being a black belt is contributing something back to your instructor and the school that got you there. So ask yourself, if i can't wait 6 months to a year, do I really deserve it?
Ou mentality nowdays seems to be the whole "fast food" situation: I paid my dues, now give it to me, and give it to me now. I think that's sad, personally.
I don't know if I really argued my point well, but i have to ask what's so bad about waiting? why do you want to run out the door as soon as you get your black belt anyway? That mentality just confirms the reason for the probationary period. If you're going to walk away from your trainingas soon as i hand you the belt, why did i even bother letting you test?
Think about waht your instructor and your school has invested in you.
now, with all that said, I don't know all the details. If they are charging you ridiculous fees for extras along the way, then look out for a scam. But if they say we want to see how you conduct yourself before you get promoted, well that doesn't necessarily spell out scam to me.
By the ay, the way it's always been usedin my system is that you get the belt after you test, but you don't get official certification until you've passed through 6 months of probation. It's a matter of giving someone the belt and the authority and seeing how they use it. Fogive me if this frame of reference has led me to misunderstand what others are saying.