In the saga films they make decisions to appeal to as wide of an audience as possible. They'll add a character that kids will love. They will shy away from showing direct violence. They'll also try to keep the plot simple and easy to follow.

With this movie, and the new spin off films in general, I think they made the decision to NOT try to appeal to everyone.

I guess it all depends on your definition of fan service. When I hear fan service I think of characters or elements added that don't even fit the flow of the film, but are added because fans will like it.

I think in this film, there are certain parts they specifically didn't simplify, even though they knew most casual fans wouldn't get it. Were they successful? I don't know. But I do think they sacrificed some box office numbers to make would would end up being considered a "better" movie in the long term.