This is not a new procedure. All international baggage has gone to baggage claim in the International Terminal since the day it opened.

From the atlanta-airport.com website in 2012:

https://web.archive.org/web/20121031...faqs.html#1.10

Q: I went through U.S. immigration and customs before getting on my flight back to the United States. Where will I pick up my baggage?
A: Several countries — including Canada, Ireland and some Caribbean destinations — participate in the U.S. precleared travel program. Regardless of the gates at which their flights arrive, Atlanta-bound passengers who arrive aboard precleared flights will pick up their baggage at the international terminal baggage claim in the arrivals hall. There are signs throughout the Airport to direct these passengers.