Legislation states that the lease is automatically renewed (40yrs, 50yrs or 70yrs depending on how the land was purchased) for residential housing, but there have been rumours saying that related laws will change so the property will be taxed during renewal.
Considering that commercial housing started in PRC in the 1980s and the first batch of houses aren't technically expired yet, I think it's pretty hard to say what exactly will happen.
Wenzhou had 20-year land leases and originally planned to charge a third of the value as a renewal fee when the first ones began expiring in 2016, but ended up waiving the fee after protests. https://www.mingtiandi.com/real-estate/research-policy/china...
by deliberately leaving the regulation vague, the CCP is able to use this regulation as a form of control over the populous.
Come the 70 yr renewal, if there are citizenry who are attempting to disrupt the power structure of the CCP, they will be the first to lose their lease (or some other method such as a high tax which is equivalent to losing the lease).
Mark my words. Regulation that is not fully well specified, and enforced universally, is basically just a political weapon.
"Well specified" regulation is also a weapon. No law is fully unambiguous, clear and without conflicts with other laws for a specific situation, more well specified a regulation is, more you need professional expertise to decode, understand, implement and certify it.
Considering that commercial housing started in PRC in the 1980s and the first batch of houses aren't technically expired yet, I think it's pretty hard to say what exactly will happen.