You can't transfer digital games, and the seller can reclaim the games, locking you out, at any point.
Amazon has the bundle. It may cost more (well, it's basically the same as if you buy a Switch + Pokemon + Pokeball), but at least you know that a) everything on it will be yours, b) you get everything you want, c) you will have a factory warranty, and d) the console doesn't have the possibility of being banned.
That's strange because the box on my amazon shows full game download
Maybe it differs depending on country distributed (I'm in the US)
If you are a big fan, you may beable to fine one of these
It's on Amazon (US and UK at least)
US:
https://www.amazon.com/Pikachu-Eevee-Pokemon-Lets-Nintendo-Switch/dp/B07H9HDDK7
UK:
https://www.amazon.co.uk/Nintendo-Pikachu-Limited-Console-Pre-Installed/dp/B07HB3HLS5
Pikachu Switch is in stock right now at Amazon
Edit: oos now
Hey, I remembered you posted about these yesterday, they are back in stock on Amazon in case you didn't see: https://www.amazon.com/Pikachu-Eevee-Pokemon-Lets-Nintendo-Switch/dp/B07H9HDDK7