Janet
I am not sure if there was a study about pumps in bags but I can tell you that
it is a potential problem.
Our regional breastfeeding task force looked at various options of giving new
moms quality pumps at discharge and voted  AGAINST placing any pumps in a
discharge pack.
Primary reason:
We all have experiences with a mom telling us that she has no milk because she
can't pump anything, or one with engorged breasts who can't get a drop out,
then for what she believes is an obvious reason she begins formula feeding.

Colostrum is very difficult--if not impossible--to pump.  We all know that
engorged breasts may not be entirely trapped milk.  Huge breasts without the
STRONG VISUAL input of flowing milk because she can't pump anything only leads
to formula use.
So far we've kept these discharge pumps out of our hospitals, I am not looking
forward to this battle again.
Perhaps your supervisors need a healthy dose of Spock's (aka star trek)
impeccable logic: why would a formula company want to give out breastpumps
anyway?  One more for the "Duh" file.
Marie Davis