we may end up seeing a lot of “singles” getting promoted on the radio and becoming “one-hit-wonders.”

I don't think it's singles that makes one hit wonders, I think it's just a lack of instantly catchy tunes. I would predict that there will be fewer one-hit-wonders, since artists would probably be focusing on making those fewer songs as pop as possible, thereby giving them more hits.

I'm not saying this is a good thing, though.