I don’t think that’s appropriate at all. It’s intrusive. If aog wanted to post he would. If he’s unable to post and wanted us to know someone would tell us. Similarly if something awful has happened to him and his family want us to know they would tell us.
Hopefully he's well, but also people just leave. They avoid announcing the fact because they don't want some tedious twit or other to accuse them of 'flouncing'.