Yeah and it wasn't like Maryland had a long history of rivalry with Duke even when they WERE in the ACC. In the early years, Maryland beat us like a drum. Then once Coach K really got going, we beat them like a drum.
It was basically just a brief stretch from 2000-2007 when Duke vs Maryland was a truly competitive rivalry. During that stretch, Duke won 11 and lost 9. And after that, we went right back to beating them like a drum, winning 13 of the final 16 against them before the series ended.
If that 8-year stretch (from 20+ years ago!) is enough to be one of the top-50 rivalries in college basketball, then I feel bad for college basketball.