I honestly think a PS4 Super Slim is more likely. Most consumers who would want a PS4 Pro would probably want a PS5 anyway, which is all but confirmed for November 2020.
A PS4 Pro Slim would run about $299.99-$349.99. But they could probably sell a PS4 Super Slim for $199.99, especially if it only had 500 GB of internal storage.
On a somewhat related note, I just got a PS4 Pro for $319.99. I've never owned a PlayStation before. I understand that people would think I should just wait for a PS5. But the PS4 has so many titles, and so many cheap titles at that. Plus the PS5 will almost certainly cost $499.99-$599.99.
And regarding all this, PS4 Slim and PS4 Pro are due for permanent price drops. They've been out since 2016. With the PS5 not very far away, they're going to have to drop their prices to make them appealing. I predict this fall we'll see the Slim drop to $249.99, and the Pro to $349.99.
Lifetime Sales Predictions
Switch: 151 million (was 73, then 96, then 113 million, then 125 million, then 144 million)
PS5: 115 million (was 105 million) Xbox Series S/X: 57 million (was 60 million, then 67 million)
PS4: 120 mil (was 100 then 130 million, then 122 million) Xbox One: 51 mil (was 50 then 55 mil)
3DS: 75.5 mil (was 73, then 77 million)
"Let go your earthly tether, enter the void, empty and become wind." - Guru Laghima