Anyone wanting to support Coast racing would have sponsored Greymouth, not Kumara, district or not.
Kumara has no infrastructure to speak of apart from newish tie ups, and as it is pakihi, there isn't much point in spending more money on a swamp.
Greymouth, on the other hand, has stabling, snd ran a raceday for Westland and probably still would, if not for that fourth day being dropped from the circuit. As it is they still run the Miss Scenicland.