If I see someone who talk about Bitcoin and he really knows well, even he didn't mention or trying to be low profile, I will consider him to have a lot Bitcoin. Anyone could claim himself don't really understand or don't have a lot Bitcoin, but knowledge don't lie.
Even they didn't show post or share their location to anyone, there's always paparazzi who will taking their photo and let people/their friends know if they meet popular person.
There are some of them who make content about crypto or bitcoin every day but they rarely mention the amount of assets they have, these are influencers who understand security and they are only trying to make educational content not just to show off. The level of crime that occurs is almost impossible to predict and no one can avoid it, so it's better to be anonymous and not share the amount of bitcoin we have with anyone.
Most influencers who say the amount of bitcoin they have don't necessarily have it because sometimes they are just trying to use the context as a way to make money. But apart from all that, it is better to be more careful and not reveal the amount of bitcoin we own to anyone.