The important sentence in the article is:
"
I own a few companies which means I'd be hit by the German exit tax.
"
We don't know how many companies does he own.
We can look into exit tax rate, in different countries:
Germany: effective tax rate of up to roughly 28.5%
Japan: CGT rate is 20.315%
Israel: Standard CGT rate is 25%
Austria: Standard CGT rate is 27.5%
https://en.wikipedia.org/wiki/Exit_tax
Change or add company address
"Änderung des Rechtsdomizils oder einer zusätzlichen Adresse"
30 CHF
Change CEO
"Eintragung, Änderung oder Löschung von Personenangaben oder der Funktion einer Person"
20 CHF
Changing company suffix
"Umwandlung in eine juristische Person"
420 CHF
Deletion (from the registry) due to leaving the country
"Löschung infolge Wegzugs ins Ausland"
210 CHF
Switzerland uses an exit tax I don't quite understand. The companies "hidden reserves" are valued and taxed about at about 17%. Those include the "goodwill" you have generated over the years, which is similar, but not the same, as the market value.
It's very good you mention Switzerland, as the contemporary German exit tax legislation traces back to the scandal with Helmut Horten, a department-store magnate who moved to Switzerland in 1968, sold his business stake and paid virtually no tax. The event prompted enactment of the Foreign Tax Act (Außensteuergesetz) in 1972, whose exit-tax provision (§ 6 AStG) is nicknamed lex Horten.