Buffet definitely was already in control of the company when he decided to list on the NYSE, in fact, recall that he bought the company largely out of pique at getting 'chiseled' on price by the existing management team during a private purchase of shares..
The only reason he listed was to get his current shareholders some liquidity; he's quite clear about this in his annual letters from the time. He had no need for or interest in the liquidity himself, and was, I would say judging from his actions over the next 20 years, pretty happy with his then-current disclosure situation. He did pretty much everything he could to keep Berkshire out of the drive for quarterly investment earnings game for public companies, and worked hard to reduce any requirements for reporting on what was going on at Berkshire.
Also, agreed, that high share prices helped him make a point that he spent many decades beating the drum on: value over price.
The only reason he listed was to get his current shareholders some liquidity; he's quite clear about this in his annual letters from the time. He had no need for or interest in the liquidity himself, and was, I would say judging from his actions over the next 20 years, pretty happy with his then-current disclosure situation. He did pretty much everything he could to keep Berkshire out of the drive for quarterly investment earnings game for public companies, and worked hard to reduce any requirements for reporting on what was going on at Berkshire.
Also, agreed, that high share prices helped him make a point that he spent many decades beating the drum on: value over price.