According to a December 24 announcement on the Civil Aviation Administration of China website:
To meet cross-strait passenger travel demand, especially the needs of Taiwan compatriots returning home for the holiday, the aviation authorities on both sides recently confirmed the arrangements and details for extra flights during the 2020 Lunar New Year period:Both sides agreed that airlines operating across the Taiwan Strait may arrange extra Lunar New Year flights from January 11, 2020 through February 8, 2020. To meet the needs of people on both sides and of the airlines, there will be no overall cap on the number of extra flights. In light of constraints such as tight mainland airspace resources, caps will apply only at certain busy mainland airports: no extra flights to or from Beijing, and limits of 147 flights at Shanghai Pudong, 9 at Guangzhou, 23 at Shenzhen, and 17 at Hangzhou.
Both sides plan to approve all extra-flight plans no later than December 31, 2019, making it easier for travelers to book tickets and plan their itineraries. Shanghai Hongqiao Airport and Taipei Songshan Airport will not be open for additional cross-strait flights during the Lunar New Year period. Airlines that originally operated cross-strait routes to and from Songshan Airport may arrange charter flights to Taoyuan Airport instead.
Upholding the principle of serving travelers, especially meeting the round-trip travel needs of Taiwan compatriots, both sides will fully support Lunar New Year extra-flight arrangements for all airlines, and applications from airlines that comply with this plan will not face any additional restrictions.
In response to market demand, airlines on both sides will also arrange some extra flights on January 9-10 to help Taiwan compatriots return home smoothly.