The most critical change is that it no longer serves as a distress alerting device in beacon mode. Distress alerting was a function of satellite monitoring, which is what is going away. So, don't expect it to get you rescued if you find yourself in distress.

Essentially, what you have now is a rather bulky two frequency VHF transceiver which takes an expensive battery (though there is a adapter to allow use of CR123 cells) Those frequencies are still in use by the military as emergency frequencies, but are not monitored or used for civilian use. You might get lucky transmitting a mayday on 243 MHz if there happens to be a military aircraft in the area who is guarding that frequency. Not something I'd want to bet my life on.

Anyway you look it it, from a practical perspective it's pretty much become a collectors item or paperweight.