Hakka milk full of nutrients???

I use Hakka on the side that I'm not using, my baby gets full on the other side. I get about 4 ounces using the Hakka.

I've been reading on here that it only catchs "let down milk" and it doesn't actually collect the fatty milk with all the nutrients, Is this true? Because I have a freezer full of milk collected by the Hakka and would HATE for all that milk to be useless