Some quick (and possibly inaccurate) summaries.
XX is gonna partner SYS for the upcoming WTT Contender series in Doha. According to Ma Lin (lead personnel for the Chinese XD team), the aim for doing so is two-fold. First is to accumulate more Olympics ranking points and second, to put the players through the test (presumably this mainly refers to SYS?). As XD has become an official Olympics event, it is necessary to come up with reserve/alternative pairings. While the goal is to clinch gold in Doha, the greater hope is for XX/SYS to have more opportunities to spar with their main opponents.
WTT Doha will mark LSW's debut after 8 months of non-competition. As Li Sun opines, they hope to ascertain the effectiveness of LSW's one-month-long, systematic training programme, and for a better gauge of the rate of her overall recovery.
On the men's side, the key objective is to put XX through the test. His form has dipped of late (presumably referring to the Mock Olympics, National Champs & ITTF Finals), especially his performance in the Singles events. It is hoped that he will regain form and confidence through winning two back-to-back Singles golds in Doha.
Due to the many procedures involved (e.g. 14 +7 days of quarantine upon returning to China) and global uncertainties brought forth by the ongoing pandemic, the CNT has decided to send a scaled-down team consisting of only 6 players. Ma Lin and Chen Qi will take point for WTT Doha. The three other players (Xu Yingbin, Yu Ziyang, Zhang Rui) who have been enrolled into the competition have playing styles that are similar to the main opponents (i.e. sparring partners). Undoubtedly, it is also a chance for these younger players to gain more experience.
So... LSW + CM for Singles & WT and SYS for XD & WT? Or perhaps SYS will be the one playing three events ~