This might help a lot of cases.
But people who make an effort to be rude will find ways around it... for example they will stay and click "no" but wont move anyway.
And for other rude people, this will give them a way to annoy an opponent who has obviously not left the game. They could click this just to make a message pop up on their opponent's screen as a disturbance.
But still, maybe this would be a good feature for chess.com to have.
As you know there are people who abandon games in a lost position and the other guy is 'punished' by then basically being stuck with the game till the opponent's clock runs down.
Its not that big a thing in blitz but in anything longer then 10 mins its definitely a source of annoyance.
So what I was thinking was that to fix it why not have a button that starts a 'claim win' countdown. So in a 15 min game suppose with 12 mins left on the clock a blunder happens and the guy bails.
Lets say A ran away and B is now stuck with the clock.
Now B, who is stuck with the clock, has the option to click on this 'claim win' button. Now this will prompt a message (like a draw offer does) on the other guy's screen along with a 1 minute (flexible) response countdown and if he is still active he simply presses the 'no' option before the claim win countdown ends and the game continues.
However if he has run away then the claim win countdown simply runs down to 0, and B wins instead of having to wait the 12 mins he would have had to wait for the win.