You have said the rule is vague in several places at what it would apply to, but I feel section 24 makes it pretty clear that it only applies if you change what radio spectrum the device would use:

The Commission proposed that certain changes in layout, included components, operating software, or variations in overall electrical or mechanical constructions that do not substantially change the overall function of the device do not require a new FCC ID. Within this category, the Commission proposed to retain a distinction between changes that may be made without an additional filing and those changes that require an application for certification. The Commission proposed to continue to permit Class I permissive changes for those changes that do not degrade the device parameters normally reported in an equipment authorization application (including a decrease in the fundamental emissions that does not increase spurious emissions; an improved spurious emission performance; minor variations in the enclosure or components; and software changes that do not affect RF parameters). The Commission emphasized that such changes could not cause the fundamental emissions to increase, the spurious emissions to deteriorate, RF exposure to increase or HAC ratings to change. Based on the negligible risk that these types of minor changes would make the device noncompliant with the rules, the Commission proposed that the manufacturer or responsible party perform the modifications without notifying the Commission or a TCB. The Commission also asked if there were other circumstances that may be covered by the proposed Class I permissive change procedures.