If you could swap Cut with uzuri then on hit you would remove the blocking aura, but it would not retroactively do more damage.
However Cut is a 3 cost and Uzuri's ability only lets you swap in card with cost 2 or less
#Uzuri swap w/ Cut through the Facade
dark lichen
native kestrel
you are correct that it would be too late for the "this can't be defended by auras" to apply in this hypothetical
umbral prism
Ahhh gotcha thank you I assumed it was a 2 cost
Looks like I need to read the card 🤣