>>25080857We knew of that scene during the weeks before XY premiered. There was a lot of intrigue about the first real romantic subplot in Pokemon, and how Serena was basically the first girl to meet Ash.
There was a few theories about how their first meeting would be, whether or not Ash would recognize her (and how he'd spend the series trying to remember), etc.
As for reactions to when that scene aired, I recall people wondering what happened after Ash led her back to camp, which is a question still unanswered. The general consensus though is that it's a cute scene, and the reason behind their "don't give up until the very end" motto.
