On Edwards specifically, I'm not sure why he was dropped in the first place- plenty of worse players still in the 22.
On farewell games, I think there is a place for them, but honestly, after 200, 300 plus matches, if you don't know your time is up, then there's something wrong.
You look at (Crows) Bassett, he retired and was still good enough for their best 22, and you look at (Swans) Everitt, who clearly had no idea.
There's a place for farewell games, but you certainly have to justify your spot.