This doesn't really seem that important if your only method of knowing this was a post blasted to hundreds (or thousands) of people. Or, to put it another way: if you mattered, you would've gotten a direct message or call from them.
I'd argue that social media has normalized keeping up with people who aren't supposed to be part of your life forever. But, we should take a step back and realize that not everything should or will last forever. If you cross paths again then you can catch up, but having life updates constantly? No thanks.