What else could it allude to?
One could argue that Christ was referring to a LOOOOONNNNNNNNGGGGGGGG time in Purgatory, but that's certainly not clear from the text.
Sink chooses to use this text (found in JPII's "Crossing the Threshold...") and transmogrify JPII's surrounding words to mean that JPII does NOT believe there are necessarily souls in Hell.
I think Sink places more burden on this text than it will bear. The cite clearly refers to a SPECIFIC sort of crime (scandalizing children) and a SPECIFIC criminal (one who scandalizes.)
At face value the cite seems to predict Hell for the criminal, and I think the face value is an acceptable interpretation.
But even in the case that the face value is not 'morally certain' it is clear that for the SPECIFIC criminal with this SPECIFIC crime, Christ foretold horrendous punishment. We know that absent a last-minute conversion, this criminal is going to Hell. What we do NOT know is only about the last-minute conversion.
Otherwise, the doctrine of Mortal Sin is in play.