Solar and wind are already cheaper than coal so it is in China's economic interests to put in more solar and wind so I personally don't think they need to lie about it. Now politicians in China fudging numbers that their cities or provinces have met targets is not out of question but economically adding more solar, wind and batteries makes more sense. I predict in 3-4 years China will start removing a lot of coal from its grid as cost of solar and batteries drop another 40-50%.

Recently I was looking how many electric vehicles China alone has added in the last 4-5 years and it hit me that had China not gone big on electric the world's oil consumption would be few million barrels per day more and the prices would be above $120+ per barrel.