Riot I believe that if in games that you should consider adding a game mode selection where it takes solo players who can fill much like an alternate to a tournament where it brings up games where an AFK: much like a disconnected player and replace them with a new join in playing the same champ as it was left when the AFK happened.
What you are saying is someone can then troll twice as hard by picking a rarely used champ and ruin ANOTHER person's day..... imagine all the galio, singed, zilean, syndra, urgot, aatrox, yorick, elise trolls. Seriously, they could their team up for failure 2 times: 1 time for AFKing, the 2nd time by picking a champ with a low chance of contributing. 
edit: not picking on those champs, just saying most can't play them very well in a pinch...
The point is that If they AFK then it's been done whether they planned it or it just happened wouldn't it be better if someone filled in to say hold lane even through passive play, besides it would only give players the opportunity to chose an AFK to fill for, like a pick and chose like if there were five AFK games currently with 
you would be able to pick one to fill for.
This game has enough issues when the team has a normal amount of time in champ select to plan out a winning team, this is just unnecessary complication and increased chamces for toxicity/trolling.
Not worth it, man.
I sort of object to the notion that because a champion is not played often, it is a troll pick. That said, I wouldn't want to fill for an afk in someone else's game just because I happen to own the champion being played.
I'm just saying that if it was possible to have a fill for an AFK that would be more desirable as even a damage soaker or at least the abilities to be used so that its not just a useless piece on a the fountain.
