It's private.
I had a close family member get very sick and then die, it impacted on my work in some ways so I told my boss, but if anyone speculated on why I was missing from work or was under performing for a few months well it was none of their business. If I left it would have been none of their business either.
People are entitled to a personal life.
Even more so when you're in the public eye, otherwise you get situations like Harry Arter who was taunted about his daughters death. Some supporters around the league have shown themselves to be equally as crass.