I do not need a solution (just sharing information)
I deleted a couple software resources (both for an Office 365 deployment) as I wanted to start from scratch and recreate them. However, after going through an import to create the new software resource, I noticed that the detection rule I had previously created wasn't in the Browse list whereas my applicability rule remained intact. Seems like detection rules are somehow tied to the s/w resource they were originally created in. However, weird that deleting my old O365 s/w resources would only zap the detection rule and leave my applicability rule.