Yeah as said the greater question would be why? As long as votes are coming in, people will like who people will like and manipulating the audience into one position or another won't greatly change that. There's only two scenarios I can think of that have merit:
- BB is worried Tim seems too certain to win, meaning people generally vote less (fans of other housemates don't bother, Tim fans vote less because he's such a sure thing). This is the general negative to the week two favourite winning, it lends the whole show an air of inevitability. So by putting Tim in more danger, votes of all kinds go up.
- BB might try to nudge the outcome if he was worried about the long term health of the show in some fashion. I'm thinking of a scenario where housemate X winning (Tim in this case but I'm not attacking Tim, any hypothetical scenario) somehow damages the BB brand because their personality/reputation reflects poorly on the show.
Outside of those two scenarios, I don't know why the show would bother.