There is nothing wrong here! It's his personal choice not to hold Bitcoin! Most of the famous billionaire doesn’t hold much Bitcoin, maybe their thoughts are different, I am not surprised at all! Recently J.K. Rowling tweeted her curious about Bitcoin and later she received some awful comment, after that, I don't think she will buy Bitcoin now, maybe later! So, it's normal, not surprising news.
But maybe Elon Musk is just tripping where he is not telling the truth after all. It will cause a massive hype all over the internet if he will reveal the true numbers of the bitcoin he holds. I'm sure that he is now also accumulating bitcoin, he is a billionaire after all and I know that his tweet is not true.
Observe the tweets of Elon Musk, he is talking about bitcoin in the past weeks and months. I know what Binance said was true, expect a billionaire like him that he also holds a lot of bitcoin.
He also tweeted about getting rid of most of his possessions including a house. What benefit does he get from lying about how much BTC he holds? He has been seen in the past as one of the most provokative CEOs, tweeting about tesla stock whenever he wants which ends up changing the price like crazy. Tesla is known as an extremely volatile stock partially because of Elon himself.
He has no reason to care about Bitcoin. He founded X.com to make online banking a thing so we know he likes to focus on security within payments. I don't find it far-fetched if he actually only owns .25 BTC, his money is probably invested in other areas.