You're probably right, though this was a successful confrontation with covid in the context of cruises, the CDC and Biden administration would use it to crush lines docking in the US under their bootheel
That said, it also demonstrates the necessity of having good travel insurance, and checking for any covid exceptions before traveling. Being disembarkes, spending a period of time in a foreign land and returning home is expensive. From personal experience the lines are quite helpful in circumstances like this, but don't pay your expenses. I suppose it's possible in this circumstance they're doing a bit more, but I doubt it.
The Mein Schiff 2 is a 2900 passenger ship and only had about 1,000 passengers aboard. I am sure the reduced passenger capacity was required by "Authorities" before they were allowed to sail.
I hope this doesn't give our CDC any ideas on cruise ship capacity. -Tom