Couple different layers to this one. Basically, for the last few months the very few flights between the US and China were on Chinese carriers as China had suspended US carriers from operating in China. After a threat to suspend those carrier’s operations by US DOT, CAAC agreed to first allow one and later two daily flights from US carriers. So just restoring US access took a big diplomatic showdown. But underneath that you have to keep in mind, foreign nationals are still barred from entering China. So these flights are mainly for returning Chinese citizens (of which there are many hundreds of thousands globally).

While Beijing is rightly paranoid about intl travel reseeding outbreaks, I think most of these flights will be routed through Shanghai instead of Beijing and probably strictly monitored/quarantined. Having other flag carriers running flights isn’t ideal, but I think its a concession they were willing to make as the citizens stranded overseas were causing bad PR inside China for the regime.