Probably does, have no way of knowing to be quite honest. I run my reactors in reverse so it forces the water down into the carbon to prevent any tumbling that may occur.Although reactors are much more efficient do you think fine carbon dust doesn't develop in there and escape into the water column also? I'm sure it does in microscopic amounts.
Fine dust, maybe, but certainly no where near the amount that putting it into a filter cup with water crashing into it will.