I often get in the discussion with nonprofit boards and execs over the topic of board members' requirement to give and get money. I have maintained that there is no "requirement" to give unless the board collectively decrees such a requirement. In this case of course, the decree should be in writing (a product of a board meeting minute) and there should be periodic discussions in the board meeting about how that is going.
For the most part I believe board members should give "something" and that there are fundraising consequences (particularly on moving others outside the organization to give) for not having full participation. But, unless members come to a collective agreement, there is no inherent requirement.
That said, here's an interesting Social Edge article on the matter.