Just visited the Coromandel and on a trip to Cathedral Cove we discovered that access is sort of closed to Cathedral Cove itself. The walk (which, by the way is advertised as taking 45min, but we did it in less than 30 almost in the dark) takes you to the beach next to Cathedral Cove, and then you walk through a big rock arch to get to C.Cove itself. The local council/Dept of Conservation/whoever, has signs up at the start of the walk and at the rock arch entrance saying access is closed due to a high risk of rock fall in the arch.
There is no mention of recent rock falls, and I'm not sure if they have occurred. It sort of doesn't say access is banned, just a stern warning that says don't proceed. By way of denoting restricted access a thigh-high rope fence has been erected across the rock arch entrance. It's hardly a significant barrier and while we were there some tourists went on through the arch to the cove.
Anyway, beautiful place, I'm sure it would have been even better if the weather hadn't been grey and windy.