Same here. Based on that other chapter a little while ago, it makes me wonder if that world still exists in some manner? How else would they know about their other forms otherwise? I'm also hearing rumblings that we're only halfway through our flashback right now, not that I mind since it's pretty interesting at the moment.
On an unrelated note, I was very disappointed by the Yankee-kun to Megane-chan ending. So very disappointed :c
"A reader lives a thousand lives, the man who never reads lives only one." - George R.R. Martin