If a flight is removed from the timetable in advance (weeks/months out), it is almost always coded as a schedule change, not a cancellation.

JetBlue’s policy, while a bit less generous than Delta's and United's (2-hour threshold), is more generous than American's, which is 4 hours.

These are airline policy decisions—not DOT mandates—so accordingly, a DOT complaint is unlikely to succeed.

A better strategy is probably to call back and speak with a different agent. Ask for an “even exchange due to involuntary schedule change.” If there's an earlier departure available, you could press for that for no change in price.