I don't see any problem with companies making an offer to attendees. If it's a "legalistic" sticking point then a group such as DevPress could simply say "send us a copy of your registration receipt" or similar and be done with it - no official endorsement required.

Aside from that, someone at the Foundation could realize "Oh wow, this might help stimulate attendence"

Problem is, there are younger minds over there will little if any substantial business experience.