I gather it has long been lamented that A380 freighter conversions are a non-starter due to the design of the passenger aircraft. Plenty on this topic online to tell you why.
Airbus cancelled the A380F project when the orders from Fedex and UPS iirc were canned.
As for future passenger use by the Legacy airlines that bought them?
It will either be a very handy people mover, or they may go to the scrapyard.