This is bypassing the entire question. DROP RATE is not the same as a SHORTLIST.
A low drop rate would be, for example, having a 0.000001% chance of getting Belfast and 50% chance of getting Makarov.
A short list means that, unless you already have a Makarov, there is a 0% chance of getting a Belfast.
We expect infinitesimally small odds of getting what we want from a single container - no chance at all is unforgiveable.
EDIT: I am complaining that we haven't had an answer to the shortlist question, not saying we have incontrovertible proof that shortlists exist