That's what none of us can really know. From the outset of his 'second life' in WWE, I figured he was fighting strictly for money.....that he didn't care about his billing, his place in storylines or what championships he might win. It seemed to me he would be happy to lose to Duane Gillberg as long as they paid him an obscene amount of money to wrestle a few times a year.
After he walked out on a Raw episode last Spring, didn't you wonder why? Was it ever truly explained? If he walked only because of negotiations over his next WWE contract......well, that's just the money thing again. But if it was a dispute over creative plans, perhaps he had some of his own ideas about what titles he might win. Possibly.
If backed into a corner and forced to choose Brock's motivations, I'd say.....in this order......money, money & money.
Never mind whether he'd serve as IC champion, I think he'd stand on his head and whistle Dixie as long as they keep padding his bank account.