I don't know if it's correct to call China a "dictatorship" but I'll humour you for a moment. The idea that dictatorships have everything under control and can conduct themselves however they please is true ... until the point that it isn't. So while a dictator technically doesn't necessarily
need to justify themselves or to have a reasonable, fair plan for some given situation that pleases their subjects - they
probably don't want to needlessly push things too far if they can help it.
However in this case a badly managed change in their Covid strategy doesn't collapse the country or cost the CCP their control over China, but it could cause a bit of a power struggle within the party as factions jostle for position and attempt to shift blame and some higher-ranking politicians will probably lose their position or go to jail for reasons. If you're one of those people, you probably want some kind of plan.