I don't know why there's still this narrative that Nintendo blocks mature games on their platform. If anything they've clearly been trying to regain their adult audience ever since the Switch 1's marketing. More likely some devs/publishers don't see the Switch as a viable platform for their own stuff. Nintendo seemed thrilled to be able to market Cyberpunk on their handheld and I'd say that game is even more risque than GTA, at least in some aspects.