The big thing about the Old Spice Classic, at least going in, was getting at least one really good out-of-conference win. When you look at Maryland's schedule, there's not one big OOC opponent on it, which was why getting a win over a tournament team down there was so big. A few good wins over ACC opponents just doesn't cut it anymore - OOC wins are just as - if not more - important than the conference wins themselves. Getting at least one is a must, and the Terps got one against Michigan State.
A few days later, the Terps toppled Michigan, who had recently beaten highly ranked UCLA. But it gets better - Michigan just beat #4 Duke, by about ten points - that's two big wins over top 5 teams for the Wolverines, and they're 6-2. They'll almost certainly make the tourney, and that win will look very good on the resume.
Let's assume the ACC is a random jumbled mess of games like normal. There'll be a giant cluster of teams that are bubble teams for the tourney, and to the committee, they'll all seem pretty much the same - these wins might save Maryland come March.