Yep, gotcha, but not what I meant.
My point was that literally all previous main Dragon Quest releases were planned and released on already proven winning systems. Actually to the point that they often waited too long and released the first DQ a the system after it had peaked, often even after the successor console is out (eg DQ7 for PS1 after PS2 was out, DQ10 for Wii after it had faded out, and last year DQ11 on 3DS well after its peak because Switch was out and dominating).
So planning a game for PS4 before it was even out was unprecedented, and given how badly PS3 limped along to fourth place in Japan, the only explaination I can think of is it originally started as a Wii U game, but then as Wii U proved a flop they moved it to PS4? PS4 sales have been propped up by releases like DQ instead of getting them because it was already successful (and potential western sales of course, but that makes no sense for Japan-focused series and titles).
I guess PS4 was kind of lucky to be released at the right time, PS3 was very old and had only ever sold bad to medicore over a long period of time, but had become the 'default' home console at the end due to Wii fading away years ago and Wii U tanking. PS4 was released into a 3DS dominated market as the only 'better than PSP/3DS' graphics machine with even a chance at viability, so if you were starting a project it was there, PC, mobile or nowhere.