I thought the slots were allocated to airlines accordingly at a cost, those airlines pay for those slots regardless if you use it or not a bit like day care. I would think all domestic airlines will still be wanting theirs and paying as such. As said above the Chinese won’t be back for a while so if international is open and they still don’t use them not sure what would happen. I would hazard a guess those unused would remain for foreign or VA/QF and JQ to pay for and use internationally.
SY airport does not seem to have much info on how and who these prized slots are allocated to.