If the gout is articular from excessive protein in the diet that damaged the liver and kidneys, it will likely be a lifelong issue.
If it is visceral gout from excessive calcium damaging the kidneys, it is forever. The kidneys don't regenerate.
However, by the time the kidneys are that far gone...
It sounds more like articular gout than visceral gout.
Visceral gout is from excess calcium.
Articular gout is from excess protein.
20% protein is excessive for a rooster. Mature roosters are much better off with 13-15% protein.
Infectious synovitis is also a possible cause.