Yes this is true.
The article (I need to try & find it again) was talking about the possibility of expanding a relatively "untapped" food source to a global scale for humans & animals. With the weather, wars, economy etc.. becoming more unpredictable, it could be 1 possible answer to food shortages & famine.
Did you happen to try any carp while you were in Germany? My other half happens to be German. She's also been in these restaurants you speak of although she's never tried it as she's put off by the "earthy taste."
I've never tried it personally - A) for the obvious reasons, it just seems wrong & B) I don't like the taste of most fish anyway.
Although, if I was starving, it would likely change my views considerably. 😂