Isn't this just a test case for developing even steeper approaches that could pave the way for us seeing a small number of movements during the night? In such cases, flow rates would be small and 160 to 4 would be less of a significance.
I can't speak for others but for us at Emirates, our illustrious leader has for many years commented on the need to develop steeper approach technology to enable night time operations at Heathrow. We have seen the A318 handle the 5.5 slope at London City so it begs the question if we will ever see a A380 fly a RNAV approach, with a profile of more than 3.5 degrees.