Can a constituent's Primary Development Role change over time?

Yes!  Keep in mind, a donor’s Primary Development Role is not a static role over time – it can change each year as the donor changes groups/constituencies (e.g. moves from being a Parent to a Parent of Alum).

Because of this, running a gift query for a time period that spans multiple campaigns (across multiple fiscal years) could cause a donor’s gifts to show in two different roles.