Larry Fink's actions can be likened to a situation where a friend discourages you from pursuing an investment opportunity, but secretly invests in it themselves.
It is very different than a friend case. Because as a person, your friend probably were fearful that he did make a bet, nothing more than a bet. Like years ago, many people accused Bitcoin is a fraud and I can understand that some people did not want to be asked about their investment in Bitcoin. They want to have easy life, investment is already stressful and they don't want to be bothered by such stupid questions as "Why did you invest in a fraud, Bitcoin?"
With Larry Fink, it can be different as they are whales and each of word from whales does have big impact on the market. If they silently invested in Bitcoin but said bad words, fud Bitcoin in the past, maybe they planned to do it to have more chances to get cheap bitcoin.
Six years is a long time for an individual to change his perception of an investment. He has waited for these years for bitcoin to collapse but it kept on going stronger and stronger. Now he understands that he is missing out on an ample opportunity to make some profit. With the bitcoin halving around the corner and favorable news about the currency, Larry Fink has no other option but to invest and publicly dispute his past wrong statements.
We can not know as he could change his mind from bear to bull or he was bullish about Bitcoin years ago in his mind but just his mouth is bearish.