My hypothesis of this is that, this is happening because a lot of people were unable to acquire the PS5 at launch due to supply issues, and by the time the supply issues resolve themselves interest was lost and the customers were like I'll just get the next one, then the next one ended up being $200 more but since they had already missed the previous iteration and they don't want to buy a downgrade they were forced to either stay with their current PS4 or by the upgrade.
My point is I don't think that this is a sustainable model, the more they increase the price the more app that the everyday consumer is going to say man this isn't worth upgrading between the base model and the pro model, and while they might see short term profits rise, instead of buying both models people will only buy one which will lower long term profits