Also,
Speaking for myself, I would hesitate to devote an hour or similar of my time to a feedback session run by the WMF. Partly, because I would want to be compensated for that time;
Looking at this list and many many other fora there is scarcely a shortage of free advice from Wikimedians with their thoughts about what the WMF is, isn't, should or shouldn't be doing. Starting to pay for it is probably not a great use of donors' funds ;)
Chris