The game wasn't build from the ground up on the Switch, so this look is what you'll get. But it's Pre-orders are already on the top 25 of the eshop AND it's coming out this close to Christmas, it's going to sell.
That said, you have to remember the average Harry Potter fan isn't a hardcore gamer, as long as the graphics are good enough they won't care and for a more causal audience, yes, this is good enough. They aren't aiming for Pikmin 4 or Luigi's Mansion 3 level here because they know they don't have to. Have you seen a casual player play a game? Frame rate means little to nothing to them. They'd easily accept it and not notice it.