Only if you shift the cost of those programs to the Federal level but not the income to support them? Yes, if Ontario could maintain the level of income (taxes, etc) they have now but not have to pay for things that they pay for now they would be in the black. I think, though, if the split in jurisdictional responsibility was different....so would the split in where the tax dollars come from and go to.
That's a good point. I wonder how much healthcare spending in each of the Provinces could be counted as "duplicate spending", i.e. spending that wouldn't be required multiple times if healthcare were a federal responsibility. I'm thinking specifically about overhead, bulk purchases (supplies, drugs, etc).
In all likelihood though, the savings would be pennies on the dollar in such a transfer. Any transfer from one level of government to another would probably result in an increases in taxes at one level, and a corresponding decrease at the other, so neither government would be "further ahead" at the end of the day.