I think it's the opposite - Brown doesn't want anything to do with him, just as he has disavowed social conservatives.
He's trying to move towards the centre - Doug Ford doesn't help.
The Tories want DoFo to 1) win a Toronto seat, 2) fundraise and 3) shut the fuck up so he won't ruin it for the rest of the province.These two sure seem to enjoy working together to take down bi-elections contrary to what you have said above.
Pretty sure the Brown Conservative are interested in winning, surely there are some upset far right wing nuts still around. But not sure they even matter too much these days as the Party changes to try to gain some form of relevance again. How much of a problem Ford is depends on which media organization is discussing it and for what purpose. No matter if Ford runs City or Province all indications are that they will be partners in "crime" should he happen to win
This was not only an opportunity to take a slap at the Liberals it was also likely a friendly gesture to Ford from Brown himself being such a critical part of his campaign.