Itīs pretty normal if they are flying to a muslim country not to serve pork... the same they will serve halal food or airlines flying to India they donīt serve beef and they usually have plenty of veggie food, or airlines flying to Israel they offer Koser food...
Egyptair donīt serve Alcohol in any or many flights, at least in the ones I have taken, nobody flying to Saudi Arabia serves alcohol.
Itīs pretty normal for airlines to adapt to customer preferences..