Was Lando technically still in charge of Cloud City even though it certainly seems like he abandoned all of it for good and put all his stock, so to speak, in the Rebel Alliance?
It seems after the death of Palpatine and Lando's departure the following occured:
In the absence of a baron administrator, a council of business representatives came to run the city
Wookiepedia: Cloud City
Although I'd love to quote anything else. The canon game this is referenced from had it's servers shut in November 2016.1
It goes on to say:
Before word of the Emperor's death could reach the city, Imperial Governor Adelhard established the Iron Blockade over the entirety of the Anoat sector, shutting down travel and communications in and out of Cloud City. The city would also serve as the location of Governor Adelhard's personal chamber located within the prime tower. Ultimately, a militia led by Lobot would succeed in relaying messages to the New Republic, and with the aid of the Uprising, would successfully liberate the city from Imperial control.