It's true that labs were pushing boundaries, the Wuhan lab as well. But every time they succeeded in doing something novel, they were celebrating it in the media.
If they really had been able to reach this major technological breakthrough, one would expect that they would have made this one public as well.
I would say that it's more likely that this was a natural mutation that got its chance to survive natural selection because of the lasting and intense contact with human researchers in the Wuhan lab.
There are some media sources that show that researches didn't take too many precautions with avoiding this contact. E.g. there are pictures of researchers without wearing gloves and one that's even showing bites from bats.
It depends how quickly the mistake was made. Totalitarian states are not famous for admitting mistakes, in fact they hide them with all their tools. So I don't think your media hype story is a good explanation.
I would say that it's more likely that this was a natural mutation that got its chance to survive natural selection because of the lasting and intense contact with human researchers in the Wuhan lab. There are some media sources that show that researches didn't take too many precautions with avoiding this contact. E.g. there are pictures of researchers without wearing gloves and one that's even showing bites from bats.