Was there some circumstance on the reddit thread apart from tickets booked, zero changes made?
The only things I've seen have been issues where people didn't realize that changing part of a ticket changed the whole ticket. For instance, if you change the outbound of a round trip, the whole confirm is considered changed. Or, if SW messes with your flights and then you take advantage of a free change as a result, that still counts as you changing your ticket. Using same day standby on the way out also impacts the way the system reads a return for round trip confirms.
If you really booked in March and haven't touched it since, I wouldn't be concerned.