You kind of made it sound like it's a cheap movie now that feels big. He didn't say it's not huge in terms of budget, he said it's not huge in terms of 50 Predators running down a hill.
The budget is still greater than ever before.
And the way he says "it's cool if we use him [Arnold] and there' a story to be told if we don't....I'm not going to tell you what we chose" sounds like Arnold won't be involved, considering Shane is more about the story.