Just curious, is this ELT on VHF121.5 or UHF406? I can't seem to find that answer anywhere.
I understand the reasons for transitioning to 406 but I would have thought it more prudent to continue at least limited monitoring of 121.5 by satellite until no more were left in use. That one thing alone might have had a very positive effect here due to 'line of sight' being better than terrestrial.
Good that 121.5 is still 'guard' for A/C, at least someone might catch a signal when that's desperately needed.
You may be aware/interested that the old HF maritime 'guard' requirement on 2182 kHz has been abandoned, leaving a significant number of private sailors who don't have ELT's out in the cold once out of VHF range. Most of that private traffic switched to the 14.300kHz Ham "Maratime Mobile Net" freq but the commercial shipping switched to satcoms, with almost all just dumping their HF radios completely. That too might have been a grave mistake.
You can't stop progress I guess, even when it goes backwards
Best Regards!