People keep repeating this but I don't think it's true.
My comment is solely sourced on my direct observations on my network, maybe 30-45 minutes in.
Everything except a few /24s disappeared from DFZ providers, but I still heard those prefixes from direct peerings. There was no disaggregation that I saw, just the big stuff gone. This was consistent over 5 continents from my viewpoints.
Others may have seen different things at different times. I do not run an eyeball so I had no need to continually monitor.