But the key points both from chapter 1 and chapter 5 are that Chono never interacted with anyone in his class, so I find it hard to imagine that suddenly there's "rivals." That's not to say that that's not what's going to happen, no, but it would seem entirely contrary to the narrative for the author to do that.
I'm also having a hard time trying to figure out the author's "rules" here. Because on one hand, you have Chono getting and successfully using a telephone number received within his dream, demonstrating that the "past" (or just, "past prime" I suppose you could call it) can affect the present; but then on the other Asakura's hair has remained the same in the present as if Chono hadn't helped her get on the bus in the past.