I think MIcrosoft kind of planned this. Now the PS4 has to at least match the One X is power, and I don't see components similar to the One X going down considerably in price unless a deal is made or PS4 doesn't release until 2020 or late 2019. By this time they'd have to either release a 450+ console, or something weaker than the One X at a cheaper price, or like I said earlier, they'd have to have one hell of a chip deal with AMD. But let's be honest, PS5 has probably already neared the end of development and specs would have to be based on 2016-late 2017 or early 2018 tech.
This is a really strange position for the PS5 to be in and if they really don't want to ignore the Nintendo Switch, and implement a portable option, then prices shoot through the roof as mobile chips the power of Xbox One X don't exist, and if they do they aren't in consumer electronics yet. I think their best bet is to sell a $450+ console and see where it goes from there. And considering One X isn't Microsoft's next console, it's just going to be really strange. Generations are already dead, this next "generation" will finish the notion of them off.