I'm sure there must be a far longer history than that. Certainly I recall bands going back a decade or two - but a lot of them tended to be bad hard-rock/metal bands, where the parameters of the genre itself probably felt oppositional enough without needing to go any further structurally or lyrically.
But there must surely have been more interesting things happening on the artistic side long before that. I recall Mukai Chie for one playing at a festival in China in the nineties that was shut down by the authorities. My guess would be that a lot of stuff happened that wasn't documented to any great degree. Or if it was documented, it never got distributed outside China. Maybe now things are more open we'll finally see some documentation appearing.
Perhaps the guys at White Noise in Hong Kong (
http://www.whitenoiserecords.org/) might have a better handle on what was happening in the mainland...
Li Jianhong's stuff always seemed very aware of, even informed by, Japanese noise. You can read his Japan tour diaries from last year in English from the links here:
http://inezha.com/p/4661167
