They're sticking with that $399 price point.
They have with the PS4, they have with the PS4 Pro and they have with the PSVR, Sony loves that $399 price point, it's the sweet spot of being an affordable console at a satisfactory price, wouldn't be surprised if the PS5 will be sold at $399, even if they might need to sell it as a loss, Sony's shareholders love that price.
I think you're seeing a supposed pattern where there is none. They decided on $399 as an appropriate price for the PS4 in 2013, which it was, but it may not be so in 2020. The Pro and the PSVR may also be $399 specifically because they didn't feel a mid-gen console and an accessory should go beyond the price set by the original - this doesn't necessarily apply to a whole new gen. By the end of next year it will be a full 14-15 years since $399 became the standard console launch price (not counting the really gimped 360 model), and the Pro and X show just what can be done with that extra $100. $399 isn't a sweet spot, it's a price that has seen success in the console market because it's always been put up against more expensive competitors.
They could still do $399, but I think they'd need to take a loss to make something good. The price doesn't need to be $499, but I do think the unit cost needs to be around that.