I got it confirmed yesterday from an account.
If you already own the coins and have some document that can proof when they are bought, and the period is more than 1 year since, then you can exchange them to money tax free in Germany.
It means, relocating to Germany to
cash out your
cryptocurrency can be well a ultra valuable way of avoiding taxes on your crypto.
The tax advisor also said, it doesn't matter how long you have lived in Germany, theoretically you relocate to Germany, cash out your coins, and can move on to the next country.
As I understand it, it will not be feasible to move back to the country you came from since they will tax you. But you could use the money for
investment in another project.