The is a Quantum Mechanical description. Yes it applies to black holes, yet in practice the wavelength is so small as to be pointless. Note that the wavelength and frequency is defined as probability waves. Getting into interpretations is probably too problematic here. The consequences is that if you had a few trillion trillion times longer than the life of the Universe you could get black holes produce an interference pattern in a double slit experiment. Not a consequence worth thinking much about.
I do not think that space-time flows, rather photons and other matter flow in space-time. If E=hn does -E=-hn ie. dE=hdn? For a black hole we can use Albert's photo-electric effect but reverse it (Sammy's electro-photic effect) and use anti-matter, then we should get photons going backwards in time ie. going back to the source and let the source be the black hole. This is a linear model like simple relativity, but we could also use GR for a gravitational model.