Is it true that Shaoxing’s new policy prevents retired people from working in enterprises?

Yes

Retired members of the former leadership team of party and government agencies, civil servants holding leadership positions at or above the county level within three years after retirement, and other civil servants within two years. Within the period, they shall not be employed by enterprises or other for-profit organizations directly related to the original work business, and shall not engage in for-profit activities directly related to the original work business.