Vol. 2 question - Does the Switch 2 upgrade apply to physical Switch 1 copies?

hi there. it seems that the switch 1 eshop listing implies that there's a free upgrade to the switch 2 version, but i'm wondering how that works, exactly.

is it just a performance patch, like the vol. 1 update before it, or does it straight up give you access to the switch 2 version? (with the new, generic otacon line and any other major differences)

and more importantly, does this apply to the physical versions too? for cross-gen switch 2 titles, i prefer the way the switch 1 cases look over their switch 2 counterparts, plus it'd be nice for consistency with my vol. 1 copy.

at a glance, obviously the way to go would be to just bite the bullet and get the switch 2 version, but i just want to inform my opinions and see if there are actually any pros or cons to it lol