No way it's going to be free lol.
1) Cost. It's going to be a huge, huge additional fiscal burden never undertaken by any other government. If they can rack up huge debt when they are making off money from land sales (cash inflow), you think they can do a full compensation (cash outflow) in the future? Especially when China will be shrinking demographically in the coming decades where there might be more homes than people?
2) Inequality. Say if some tycoon owns 10 luxury apartments in downtown Shanghai, he can pass them down to his descendants in perpetuity? And with appreciating home prices, taxpayers have to pay his descendants a full CMV compensation of 10 luxury housing in downtown Shanghai every 70 years? His descendants can just collect rent from the new luxury home forked out by taxpayers? Meanwhile the poor and their descendants will be condemned with a much smaller compensation (or even no compensation at all), just because their ancestors did not buy a luxury apartment at low prices in the 1990s?
Effectively it will be a large systemic transfer of wealth from the poor to the rich, and it will be a recipe for disaster.
Any compensation at CMV currently is more like the exception than the norm. The vast majority of housing in China were built fairly recently, so they only have to tackle the problem in a few more decades. There is still a lot of ambiguity.
Their state media (Google Translate):
进入3月份,楼市迎来传统的“金三银四”销售旺季,许多房企趁此升级购房优惠举措,希望带动自己的销量增长。值得注意的是,房屋的土地使用权并不是从购房者签合同买房的那一刻开始算起,而是从开发商向国家申请拿到土地的那一刻开始计算。
cn.chinadaily.com.cn
I think they also know it's not possible to give free compensation for everyone, but clarifying it now will probably shake market's confidence and affect prices.
In Singapore, we also have 99-year leases. And the official stance is, yes, the value will go to zero after 99 years. That's how you 'close the loop' and recycle land for future generations. Might not be popular, but necessary.