Theoretically, Switzerland allows for foreigners immigrating to the country a one-time opportunity to negotiate long-term favorable tax deals to lower their tax rates. This is only available to non-Swiss foreigners with significant assets moving to Switzerland, because their assets become subject to the Swiss wealth tax.
But despite what they said to the media, they weren't moving because of the wealth taxes. If they were moving because of the Scandinavian wealth taxes, they would have moved to the U.K. or the U.S., which don't have wealth taxes at all. Instead, they moved to another country with a wealth tax and a relatively high income tax.
So clearly it was never about the taxes. It was either politics, or they just liked Switzerland better. When you're super rich, Switzerland is a much nicer place to live than Norway or Sweden.