I eventually tracked down the NOTAM concerned..
SBRJ N0016/19 - AIS WAITING FOR CONSOLIDATION OF UPDATE IN INVOLVED SYSTEMS;
PLN, AS OF 4 AUG 2017, SHALL CONTINUE TO CONTAIN,IN ITEM 15 AND IN ITEM 18, THE FOLLOWING INFO:
1- INSERTION OF SEPARATE POINTS FOR NOT MORE THAN 30 (THIRTY) MINUTES OF FLIGHT OR FOR 370 KM (200 NM),WHEN IN FLIGHTS OUTSIDE ATS ROUTE, INCLUDING EACH POINT WHERE SPEED, LEVEL, ROUTE AND/OR FLIGHT IS/ARE PLANNED TO BE CHANGED.
Strange the AIP hasn't been updated to incorporate this though.