What exactly are the differences between Legends Z-A on the Switch 1 and 2 and the Upgrade Pack?

Question

I figure this may be too soon to ask, but I figured it can be answered as info comes out.

This is what I'm wondering:

In Japan the game will be priced at 7100 Yen for the Switch version and 8100 yen for the Switch 2 version. The upgrade pack will cost 1000 yen. Via Serebii

I'm very confused as to what this means in particular. Are there differences between the two? what would an upgrade pack do?

Thanks!

Answer 1

Includes:
Improved performance with higher frame rate and resolution
Nintendo Switch game: Pokémon Legends: Z-A

The switch 2 version just has a higher FPS and better resolution, and the upgrade pack lets you upgrade a switch 1 Z-A cartridge with the same graphical changes (but only when used and purchased on the switch 2) source