Bloomberg: At least 11 studios are in possession of a 4K Development Kit for the Nintendo Switch.

[Nuvendil]

I don't think I saw anyone mention that Zynga, the one source he names and therefore we know is real, responded after being asked if this is true and said...no. xD

And before anyone says it's an NDA thing, if Zynga needed to abide by an NDA the most logical and easiest way to make sure they complied and didn't accidentally give something away would be to simply ignore the inquiries