Kim this is an important distinction.
All free cultural works are open, but not all OERs are free. To be fair to the Declaration team -- this is not labeled a "Free/Libre Content Declaration" -- therefore we can expect signatories to the declaration who do not necessarily support the essential freedoms.
However, I would like to see a clarifying sentence or two which distinguishes between the free and open (non-free) participants of the OER movement.
A reference to the free cultural works definition or similar articulation of the essential freedoms would be beneficial to the declaration. When thinking about our collective responsibilities - I do think that its important to reflect that their are differences of opinion in the OER movement and that free culture perspective is not clearly identified in the document.