Yeah this doesn't make any sense to me either and I had the SAME question when I was reading your original post.
Here's my thinking... I'm already using their Multivitamins which gives me 100% of what I need .
Then they say I HAVE to have a meal replacement as well... but isn't a meal replacement the same thing as a Protein supplement with Vitamins and minerals added?
So if I'm already getting all I need (Vitamin and mineral wise) from my multivitamin, why would I want MORE vitamins and minerals from a meal replacement? Wouldn't I be getting overdosed on vitamins this way? Not to mention throwing away hard earned money? Lord knows I don't go to class and try to get middle school students to enjoy math because it pays well! :-P