Google has provided me with much confusion.
Much the same in the UK. The SARSAT that operated on 121.5 produced an excessive number of false alarms due to the large number of devices around the World capable of transmitting on 121.5 MHz. 406MHz had long been the ELT frequency and such devices were removed from aircraft in the UK untill EASA appeared then they started to re-appear. PLBs now operate on 406 MHz for sattelite pick up and as you say also provide a weak homing signal on 121.5 MHz. Having flown aircraft with homers for many years, they were always on 243MHz the military frequency, not 121.5 MHz the civil frequency