I don't have time to find the reference, but Airbus say somewhere that if "LAND" is displayed in green on the FMA below 400' RA, there is no failure that will prevent the FLARE mode from operating.
Not sure if that is true - they might have been referring to probabilities of failures. This is a tricky area: PF should be eyes outside by then, so s/he doesn't know when the RAD ALT is at approx 40' (when FLARE should normally be displayed), so how does s/he know if FLARE is missing until it is too late ?
At a recent CRM course, a Senior TRE seemed to be telling us that Airbus have not banned a 'NO FLARE' call.
However, as Fursty says; if we are not supposed to say 'NO FLARE', then I think the most sensible call in the absence of FLARE would be to say 'GO-AROUND', (which should be reacted to immediately), There isn't time for much else before hitting the ground.