I never took carbon freezing lifeforms was “crude” or even unusual in the Star Wars universe, but that the carbon freezing equipment specifically on Bespin was crude, and designed with a different purpose in mind.

And even if it was, maybe the ugnaught in the Mandalorian trailer (Kuiil?) was one of the ugnaughts that retrofitted the tech on Bespin, and he was the one that designed the carbon freezing tech on the Mandalorian’s ship, realizing the potential of the idea. It is like 6~ years after ESB so technology evolving isn’t a crazy idea.