I'll answer, if I may.
Raising the capital gains inclusion rate will certainly render some business initiatives a little less profitable. We can't pretend that it doesn't come with economic costs. However, virtually no other measure targeting the rich would have less of an impact on that sort of thing.
This is not my area of expertise, but based on what's been published in Canada on the matter, it's taxing business investments that has the greatest impact on investment decisions. For example, being able to claim investment in machinery or technology as a business expense is a determining factor in decisions to invest and expand. Capital gains play a far more secondary role when making that kind of decision. Therefore, it's highly unlikely that there will be economic costs and a massive outflow of capital.