JKR didn't say she regrets Ron/Hermione, or that Harry & Hermione should have been together, nor did she try to change canon. Disappointed especially in my fellow Ravenclaw that you don't seem to have read the interview properly! (To clarify: she said R/Hr had some incompatibilites- ie they aren't perfect, as Ravenclaw said, and that H/Hr may have been a better fit *in some ways*, but she's never said that means Ron & Hermione shouldn't have been together; she's still for Hinny & Romione!)
This was actually an ask that we have had for a while now, basically since that first article came out and mass uproar rocked the fandom. That is the mentality I think most of us answered the question from, even our new Ravenclaw admin.
Even reading the interview, I stand by my response to it. I did read the transcript (link here for anyone who has not), and she is totally free to look back and regret what she did. She is the author, every author looks back and wishes they would have changed something, especially in a series as epic as HP. However, I’ll be honest and say I would have been disappointed if Harry and Hermione happened because again: the hero ALWAYS gets the girl. If there is a trio, the main character almost always ends up with the member of the trio who is their opposite gender.
But again, the responses were basically to the single article that was out, before the transcript was released, when the news was trumpeting that JK regretted her decision and blah blah blah, drama which is what gets readers.