The safety question isn't as relevant anymore as it used to be when it was discussed back in the days. When bitcoin had no real legal status, I think one of the major risks was prosecution based on whatever legal authorities could have come up with to blackmail him or actually set an example. Now that this is not a risk anymore in most jurisdictions, I don't think risk exposure due to others knowing that he owns that many BTC is a big deal. If it was because $5 wrench attacks could happen (which I doubt a billionaire would allow to happen), then people like CZ or Saylor would be as much at risk as Satoshi would be.

This could still be a large organizational operation to put infrastructure in place that allows authorities to track down the flows of money. There are lots of interesting issues with negligently using cryptocurrencies: all these exchanges and swap services with those easy to use interfaces (one currency against another) are gathering an incredible amount of network data. They know all the input and output addresses and can hence provide not only single user addresses, but whole maps for single users, user groups and financial flows. And then they make that data accessible to authorities either because they agreed upon sharing the data upfront as a deal to not get their services shut down, or they sell the data.

I know the second part is a bit off-topic, but I bring this up because if bitcoin is a large scale organizational or governmental operation, then the individual Satoshi Nakamoto doesn't exist in the first place. But risk because of revealing his identity should be no more of a threat to Nakamoto than it is to any other billionaire and if anyone has the means to protect against potential risks, then it is the billionaires.