This may be me talking with anecdotal evidence of a limited sample size, but ever since the newest Bilgewater event in ARAM went live, I have managed to play 8 straight games of ARAM without a single remake due to someone leaving during champion "select".
Frankly, before this, I usually got 8 or so remakes before getting a single game in. So if this change is true for people beyond me, I'm kind of curious to the reason.
I'd like to think it might be because of the Ban System that got added. It cuts down on Champions you don't want to fight AND don't want to play, so people may be getting less skittish when they can make sure they're not getting stuck on Udyr when they have no rerolls left.
I'm curious to hear if this experience is universal or if I've just cursed myself to getting 20 games dodged in a row the next time I get to play.