Summary
China's National Immigration Administration has announced that people holding Chinese residence permits for the purposes of work, personal matters or family reunion will be allowed to re-enter the country from September 28th. People whose residence permits expired after March 28th may apply for new visas at Chinese embassies or consulates.
This is a change to the current situation for entering the country. Entry for foreign nationals was suspended in late March due to the Covid-19 pandemic, and was later reopened only for holders of newly-issued visas issued on a case-by-case basis to essential staff only.
In practical terms, this means that UK and other overseas staff who were previously in China on a work permit may now re-enter the country. However, it does not extend to holders of business visas which are used by many UK academics who teach in China for short periods on a fly-in faculty model. Readers should also note that China still has a 14-day quarantine requirement for incoming travellers.
Source
National Immigration Administration: Announcement on Entry by Foreign Nationals Holding Valid Chinese Residence Permits of Three Categories - https://www.nia.gov.cn/n897453/c1344669/content.html (includes an English translation below the Chinese announcement)