You should add his information. As far as i know, all of family passports are basically attached with each other.
Better not to hide anything.
The consultant says that since my parent's annual income is only around $17K CAD the high commission sees this as a financial barrier. But we have funds over $100K CAD, does it affect in any way if I add his detail?
Under any circumstances you should noy hide, otherwise it would affect your case adversely.
Its better to be assessed with true information, rather than assessed with false/ incomplete information.
IRCC have rights to make you 'inadmissible', if they feel that something is hidden by applicant.
I've seen cases, where not mentioning about previous refusal in the application, leads to another refusal and even 'inadmissibility' to their country either for few years or for lifetime.