[searcykid (OP)]

NOAA reports that the hole in the ozone over Antarctica is shrinking.

Hole exists over Antarctica because it's cold enough for ice to form in the stratosphere. Ice is catalyst for the breakdown of ozone.

New hypothesis on why hole is shrinking.

Global Warming is reducing the ice particle density over Antarctica. Without the ice particles, the reaction that results in the breakdown of ozone doesn't happen. The result is a smaller hole in the ozone layer.

Easy enough to test. Correlate the size of the hole to the ice crystal density, temperature of the stratosphere, ppm of carbon dioxide in atmosphere, or some other metric of global warming. 

[Colin2B]

It's more complex than that. Cl is the catalyst not ice, Cl is released by CFCs which have been declining. It is true that cold polar clouds contribute to the process by which Cl catalyses and destroys O₃, but it is the CFCs that provide the Cl.
The test you suggest would not prove the cause.

[searcykid (OP)]

The catalyst is the solid (ice crystals, sulfur from Pinatubo, etc.). The solid speeds the process where UV breaks the Cl from the CFC molecule. Maybe I went to the wrong school to study chemistry, but Cl doesn't catalyze anything. It's part of the redox process.