Will these funders continue to fund arts organizations, or is this the only place I can apply for support from these funders?

AER funds are in addition to continuing arts grant making undertaken by individual foundations. However, please note this statement in the Fund Guidelines:

The foundation community does not possess the resources to return the cultural sector to its former position, or to respond to the individual needs of every organization. Organizations, and the sector as a whole, will have to think differently about how they function moving forward in order to be successful in a completely changed environment.