I can't read the content of the link you posted, but from your explanation there is no certainty that this individual was killed because they have a lot of BTC, people get kidnapped and killed everyday for different reasons.
But the message of your topic is correct, keep your privacy, don't tell people you have BTC and try as much as possible to use decentralized services, so you don't have to submit kyc everywhere. You can be a victim of a $5 wrench attack if you reveal too much of your identity to the public.
Having a lot of bitcoin will not put you into danger, but if you tend to make yourself known about it in public that you are hodling a lot of bitcoin, I guess that will be the start of living your life with possible danger. People who live with so much luxuries that they become careless and not cautious the whole time, then they are the one putting theirselves into danger. However, if they keep their privacy and live life like those who are in budget, probably they will never become any target for kidnapping or killing.
One thing to avoid this is not to post any of your crypto dealings over the internet, or on any social media channels.
Just be silent about what you are doing and don't disclose to anyone that you are into this market.
Aside from avoiding any possible danger, you won't need to explain to anyone about your transactions.
You will find out that you will live a peaceful life as you only need to secure your funds from the bad actors over the net.
The problem with the younger generations today is that they post whatever they think on their social media channels, that's where they are subjecting themselves to be a potential victim as predators are lurking around.