I'm not entirely on board with this concept. I think they went on similar, but different paths. I think Sony wanted 4K lite power upgrade in a box at a price they wanted to stick with. They did that, and they did well with the parts available at the time. I think they could have increased RAM and other things, but it would have likely broken the price point.
I think MS had a desire to put out a product using the best available parts, increased power..etc. We don't know the price yet, but it's been generally thought that this will cost more than the Pro did a year prior. Power comes with cost.
Since we don't know when either company's successor product will hit for sure, let's leave out how the ___ company's new system will release in year ___ and leapfrog the other's product. That sentiment will just ruin the point.