I really hope the multi-classing thing turns out not to be true. There MUST be restrictions and opportunity costs to multi-classing. Otherwise, everyone would do it. There would be no upside to single-classing. And in the end everyone would end up with very similar character builds. This is already enough of an issue in 5e, with everyone taking dips in hexbalde or fighter, they really shouldn't make it worse by removing the downside of multi-classing.