No, its not a change.
The NOTAM simply reinforces/restates the procedures that have been in place for over 10 years, and are plain common sense.
As I said, the FIA frequency is NOT normally the same as a high level control frequency.
In situations of remote areas where they may be common, and in other areas during periods of light workload where the retransmit facility is active, I suspect ATC are experienced enough to "tune out" mentally to the odd broadcast they hear on an FIA frequency, and "tune in" to a call on a separate control frequency they're using.