I don't think it hurts Brock at all WWE wise if he loses
if he loses a close fight by decision or in controversial fashion, he can stay babyface and the fans will be sympathetic. Then you can have a dikkhead heel like Kevin Owens taunt him about losing in an over the top manner to get heat.
If he gets his ass kicked, you can just turn him heel and essentially play the "So what he lost, Brock made more money in 1 night than any of you will ever see in a lifetime" card and have him attack one of the smart fans favorite guys.