Yeah, it turns out that just isn't true. For someone in his income range, he'd be looking at 29% in federal income taxes and 11% in Ontario taxes. That's roughly what he'd be paying in NY. Canada has some other silly taxes here and there (I still don't get VAT), but honestly, he'll keep about what he'd keep as a Yankee.
Of course, the Jays pay in loonies and twonies. So bring a sack.