I feel this is a very smart and tactical move to prove a point.
In Germany, we eat pork. Period.
Muslims in this event had the option to eat up to 15 other types of dishes including a Hallal Option.
They went and said that the pork offends them. Which means they are not compatible with German society if German society, in General, eats pork.
If they go to any market, any restaurant, anywhere there is pork.
If they wanted to have a Non pork event, what is next? a non pork city? then a Non pork country?
This is just my analyzing of why I think they decided to serve pork, to show the community what Seehofer meant when he said that Islam is not compatible.
Of course, this is just my assumptions on why they did this, I could be wrong.