Last I heard those flights weren't true flagship flights (aka with Flagship Lounge access and a full meal service plus sundaes). From the access page now though (
https://www.aa.com/i18n/travel-info/...p-lounge.jsp):
It appears that the language is gone that stated "On flights operated by 777-300ER aircraft only". Are they now treating the 772 flights as true flagship flights with lounge access, service, and sundaes?
This link does not work for me. Says "page has taken flight".