ACL,
I don't doubt ATL 777 might move out completely, but couldn't the size of ATL 777 and DTW 777 be flipped vs closing ATL 777?

I ask, because what else would do a route like ATL-NRT?

FWIW 777 routes (by my best count, I might be missing some):

ATL-DTW
ATL-LAX
ATL-DXB
ATL-JNB
ATL-NRT

DTW-ICN
DTW-PVG
DTW-PEK
DTW-HKG

NRT-HKG
NRT-SIN
NRT-TPE
NRT-ATL
NRT-MSP

MSP-NRT

LAX-SYD