I would think it's all of that plus player salaries, travel costs, etc.
And I don't think I was completely clear. I'm pretty sure the owners are saying that without fans MLB loses $640,000 every regular season they play, even those 50 they are proposing. So doing the math they are saying that if MLB plays 50 games and pay players a prorated share of their salaries they will lose $32M over the course of the regular season. But I think the owner's stance is they can afford to lose $32M on the regular season because they will make it up with the post season money.
But, they say if they play a 100 game season with full prorated salaries they will lose $64M and that's more than they can cover with the post season money.
AlbaNY_Ram