That's correct. New tracks will not be certified by the NCAA if they are longer than 200m/220y. Existing tracks, however, are grandfathered in; thus, no matter what other schools build indoor tracks over the next several years, the Dempsey will always have an advantage of being able to provide the largest (and thus, for distance events, given the long straightaways and wider curves, the fastest) competitive indoor track in the U.S.
Credit should also be given to UW Associate Athletic Director Chip Lydum, and former UW coach Orin Richburg. When the Dempsey was built, Hedges envisioned it as a football-only facility. Richburg, of course, wanted a track (since the previous indoor track had been removed in the renovation of UW's basketball arena, leaving the school without an indoor training facility), and found support in Lydum, who was able to prove to Hedges and the key project decision-makers that a track COULD be fit around the field, without adding significantly to the cost of the project or limiting the ability of other teams to practice/train in the Dempsey. Without Lydum's leadership in the administration, as well as Richburg's trademark "bulldog" determination, the Dempsey would not exist as a world-class track facility.