I'm not here to dunk on specific tutorial writers, as the piece about PyGame that I found this in is both pretty old and generally okay at its job, but offering a choice between WASD and arrow keys really isn't what I'd consider to be an example of accessibility.
Further, the way they defined WASD in the code examples that follow would make their directional control schema entirely useless on non-QWERTY keyboards.
Like, absolutely, yes, encourage new developers to consider that not everyone's configuration is the same as their own.
But this kind of feels like the concept of accessibility is being missold here.