If it is a prequalified WPS, there is no requirement (that I am aware of) to perform a qualification test of the filler metal. The manufacturer is responsible to qualify the filler metal to "certify" as meeting particular classification. The classification determines what specific tests must be performed by the manufacturer. The electrode classification indicates what gas was used, whether it was tested in the as welded or post weld heat treated conditions, whether CVN was met and at what test temperature, etc.
Al