Some people are pescatarians. That means they don’t eat chicken, pork, beef, etc, but will eat fish and seafood. Catholics don’t eat meat on Friday’s in Lent, but fish is OK
But … it’s not a simple question. It depends on the definition. By some definitions, yes. By some definitions (the Catholic one), no. By older definitions all food is meat.
I dunno, it’s a bit like asking “Is London a city in Canada, or a city in the United Kingdom?” You’re basically asking for votes on which dictionary definitions are wrong.
The question needs more context, but then would probably be less interesting. If someone says they don’t eat meat, most of the time they would include seafood in the things they do not eat, but if someone says they want meat for dinner, most of the time they would not include seafood in the things they wish to eat.
I assume that’s why they talk about the protein. Basically it’s assumed the dish is going to have some kind of protein, maybe meat, maybe not; “protein” has become the generic term that “meat” used to be, in order to open up to more vegetarian options.