First of all, the goal here is simply to meet the Chinese governments "Sustainable Development Goals." That's what "could help protect ground water" means. It's a meaningless goal from the perspective of veganism or even global conservation.
But it's also a meaningless solution. The rate of consumption increases each year. In that context, the goal isn't just, "eat 10% less meat", it's, "establish a hard limit on the amount of meat consumed, which is 10% less than our current rate of production." Maintaining that hard limit becomes a larger and larger commitment each year, with a growing population sharing a fixed amount of meat. There might be a mechanism for accomplishing that IN CHINA, but globally that is an utterly unimplementable solution to any problem that animal ag is currently causing.
We're in for a long arc.