Vanguard have stated that the reduction is in response to...

Vanguard have stated that the reduction is in response to handling fund flows. While this is indeed a feature of managed funds (be they passive or active), it is a startlingly large cut. Personally, looking at the movements in FUM of VAS over the past quarter and beyond, I suspect that the stock answer I've been given is only partially truthful. I'll do another post if I get a better answer.