Traveler was denied vegan food, stayed hungry during flight

I came through a news recently a passenger who was a animal rights activist was flying for some meetings to and fro.
During the to flight the menu had Vegan food and it was all normal but suddenly in fro flight the menu was changed.

Airline says they stopped serving vegan food due to less demand and have only Veg and Non - Veg.
And the passenger raised the issue at many platforms saying he had to stay hungry and faced health issues due to this.

I am just curious what would have you done in this case, and do you think they over-hyped the matter to promote vegan food ?