Almost certainly accidental.
If China wanted to purposely release a pandemic virus then they would do it anywhere else but than in the city with the virology institute where they were conducting gain of function coronavirus research.
I mean who would believe that the virus emerged naturally in that scenario?
It's well documented that that the Wuhan institute of virology had insufficient biosafety controls in place. They were conducting high risk gain of function research in biosafety level 2 (BSL-2) laboratories. That type of work requires BSL-3.
If any researcher in the USA got caught doing BSL-3 work in BSL-2 labs not only would their career be over, but the entire institution would have all work suspended at best, completely shutdown at worst.
And yes I've worked in both BSL-2 and BSL-3 labs.