The USA FAA Approved Airplane Flight Manual is required to have all the information required to operate the airplane safely and it is quite clear that the fuel pump is not required for takeoff.
However the additional document, not approved by the FAA, (called the Pilot Operating Manual or just Operating Manual depending on the year) has:
I rang Jerry Jr at the factory and he said that gravity feed is sufficient, in the event of failure of the engine-driven fuel pump, for the engine to run OK so just conservative to use the pump. It seems that they haven't bothered too much about tidying up these manuals in the last 40 years (several inconsistencies between the documents so merging them into a single POH would be nice).