For too long Sony has not made one last big push to increase PS4 sales (i.e. a price cut) and they aren't going to change their mind now when the PS5 is what they want to sell. The PS4 Pro's production has likely ended already, because its price point makes it pretty pointless in comparison to the PS5 SKUs. A standard PS4 for $/€300 doesn't look great when people can buy a backwards compatible $/€400-500 next generation console. Plus there's the used market which is going to have an increased influx of second hand PS4s due to not-so-well-off people trying to get the funds for a PS5 and a bunch of games.
This, took the words out of my mouth.
a 149.99$ Diskless - 199$ With Disk PS4 Mini would make sense if they released it next year even with selling at loss, since the PS Walled-Garden will make up for it, and PS4 Ecosystem not going Anytime soon due to indie gaming and Porting improved versions of 3rd party switch titles, since the switch is still at its prime
i think at first they wanted to completely ditch the PS4 for the PS5 but changed their plans at the last minute (check out Jim Ryan interview about Cross-Gen) with PS5 Titles appearing on PS4 like miles morales and Horizon 2 and a rumored GoW Ragnarok cross gen support
they even made a statement recently that the the Transitional Period from PS4 to PS5 cross-gen support will continue until 2023
Honestly im starting to believe more and more that a Super Slim and Cheap PS4 Model is coming by next year