We need arbiter back in the story.
Why does Infinite need to have the Arbiter in the story?
For what? To be there for the sake of being there? Because Halo 5 did that, and was received poorly.
Don’t get me wrong, I’m supportive of his appearance, and there’s perfectly valuable reasons for him to be part of our struggle, but simply saying “We need arbiter back in the story” doesn’t do.
But, whether he is or not, at this stage, it’s too late to change the script. If he isn’t, that’s it, no Arby. Unless you want a massive delay (which would have level designers, voice actors, etc. redoing their whole work because of a character) just to include him… well, let’s just say that a lot of people would be disappointed.