I know this is the AA forum, but DL sometimes rotates widebodies onto ATL-PHX-ATL in winter. It's not all winter, and it's only a flight here or there, I think, but seems to happen sporadically every winter. In the past I've seen 330s doing this on occasion. Looks like one of the turns becomes a 764 on 1/3/18 (schedule subject to change of course).