I can't find the guidance that came out back when OCPs were announced for the Air Force, but it did mention the academy will be transitioning to them fo the 2023 graduating class. Will find the document and post it though.
Airmen who have the old ABUs may continue to wear them for the three (3) year transition period. They may also transition right now into the new OCP uniform, if they want.
When you have to buy your uniforms, you'll find that you may not be too quick to pull the trigger for new-fangled ones.
By April 1, 2021, everyone will be required to drop the old ABU and wear the new OCP.