Nier automata director wishes for PS VITA 2 or at least a smaller version of switch, which is a bit too big for him ( as a handheld console ) !

[Lauster]

Switch (console only, without joycons) :
23.9 cm (width) by 10.2 cm (height)
(9.41 in × 4.02 in)
= 243.78 cm²

PS Vita (1st model, wifi version) :
18.2 cm (width) by 8.35 cm (height)
(7.2 in x 3.289 in)
= 151.97 cm² (even a little less, vita is not rectangular)

I put my ps vita with a soft case or my 3DS in my pocket, but ps vita is close to the maximum size I can put, so I know I can't do the same with the Switch.

So yes, Switch is bigger, and his claim sounds legit to me.