Towson was a final 4 team 2 years ago, so they aren't a good reference point regarding a trend. They were ranked #7 in the country.
While I still think "big dog" programs like Denver, Duke, Loyola, Yale,
and Maryland will still be near the top at the end of the season, the gap between them and the "lesser" teams has shrunk. You're correct that ND needs to take care of business against the Michigan and Marquette, which is no guarantee. They have little room for error - if they get thru March with a winning record, I'll be very impressed.