I would still say PC is the best option. 2 reasons:
1 - The new consoles are powerful enough but they will be optimised for a different type of game. PlanCo is not graphics intense it is content intense. So a PC that has been designed to run modelling software or render videos will still out perform consoles.
2 - Building in the game with anything but a keyboard and mouse is going to be a nightmare. As mentioned above most of the freeform building had to be stripped out of Jurrasic World to make it console friendly.
However if you don't have a properly built PC or only have a laptop these consoles will provide a reasonable alternative (as long as they support keyboard and mouse).
I believe it was always Frontiers hope that the new generation of consoles would be announced before the consoles version release.
Oh yeah of course a PC will always be better. It's a PC. But these new consoles are close to what would be classed as a high end gaming today. So Planet Coaster will shine. Probably better than it does on most peoples PCs today. As most people do not have a Ryzen 7 and a GTX 2080 GPU (which is what the consoles have equivalents of) as they are both top end components.
I've done some research and it is using keyboard and mouse on console if you want to.
I am not sure what optimised for a different kind of game means, that's not how consoles work these days. Optimisation like that is done more so on a software level on a game by game basis.
Planet Coaster, while being content intense, is still quite graphics heavy, when you crank everything up, gives a high end graphics card a good workout.
It's an exciting time because Planet Coaster will be a good experience on next gen, it will play better than it will on most peoples home PCs today, due to the new consoles power being above your 'average' home PC. Plus with a lack of API overheads you inherrientoy don't have on consoles as they dont need them, it should run more efficiently on consoles.
While PCs are faster and always will be, they use a brute force approach to getting performance, the have to, due to the vast ustomisation ane upgradability you can have. This makes their biggest strength also their biggest weakness in some cases.
Consoles do things far more efficiently because they dont have this issue. So if we have a top end gaming pc inside the new consoles, without all these overheads, we will see performance better in Planet Coaster on consoles than if it was in a PC with like for like hardware. Same story with this gen too, it's just fundamentally inherent in the way the systems are.