Infalling matter or radiation becomes ‘simply’ infinitely red-shifted (on account of the slowed time), and hence undetectable to an external observer — and is hence indistinguishable from the bulk of the prior-existing “black hole proper”.
Conversely, a particle on the surface of an object compressed to near its Schwarzschild radius should experience an extreme blue shift and time contraction. Imagine absorbing in one instant a billion years of microwave background radiation blue shifted to gamma and beyond. How could the near-black-hole hang onto it?
Yeah... basically looking backwards from the perspective of an infalling particle one would experience the full blast of the Big Bang as it occurred ‘originally’.