I expect Bloodstorm to tank PS4's framerate really hard, as even now in crowded areas PS4's framerate goes way below 30fps. PS4 Pro comes out this November and it's about 2.5x more powerful than the PS4/PS4 Slim, so it should help out with the framerate for those willing to pay.

You won't be seeing such smooth gameplay on PS4 with Bloodstorm, guaranteed, it will tank the framerate and performance a lot harder than ARR/Heavensward, but that's the price of progress. As the game improves, the dated hardware will show more and more.

PS4 won't be limiting anything for a long time, it will just perform worse and worse as more stuff is added and thrown on screen.