Interesting. Everybody wants to jump the Bitcoin train all of a sudden it seems.
That Bitcoin paper loss is probably not much for Germany, but it is something to consider. Added up, it could turn into a huge Profit to be missing on. I would have probably done the same if I was in their position.
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You can call it as a loss or not as a loss, but my opinion is it's not a loss. You can say it is a loss if you bought it with your money, and sold it at lost price.
And if you sell your bitcoin with profit, for example bought it at $50,000 and sold it at $80,000, 1 year or several years later, Bitcoin will have its price at $500,000, your profit in 2025 is still profit, it is never a loss.
It is a paper loss. In other words, Money they missed out on. This is true even in the scenario you mention. You had Profits, but you also had a paper loss caused by not taking Profits at the right time.