I think it varies from game to game. Blizzard might be trying to do the best switch port of diablo 3 possible.

In contrast, Sumo's Snake Pass took a week to port to switch. A lot of developers have said Switch hardware is friendly for porting games over, more so than the Wii U.

Bet with Intrinsic:

The Switch will outsell 3DS (based on VGchartz numbers), according to me, while Intrinsic thinks the opposite will hold true. One month avatar control for the loser's avatar.