This does not answer my question, unless you also have proof that the amount of cases of the ISS crew having to take shelter is also increasing exponentially. Since the astronauts went back to work after 1 hour instead of moving back to Earth, we can infer that the perceived danger has passed.

(That is quite beside the point that Kessler syndrome at that altitude is definitely not the type of "exponential growth in a finite environment" that the linked article describes, because orbital decay means that the smaller the particles get, the faster they will deorbit themselves)