Will it be lost (Nintendo E Shop)?

We have a problem:

I was paired with my Gmail account on my brother's switch. He had bought games on the Nintendo E Shop account and also bought items or packages in these games. Now I want to remove the account and put his on it. Are all of the purchased games that were purchased in the Nintendo E Shop lost with the purchased items or not?

More detailed explanation? Unfortunately I only understood the train station.

My Gmail account connected to his Switch, Nintendo E Shop. He then bought games and these packages in the games. Want to switch accounts. Are games etc lost?

Wouldn't it be wiser to just create a new user? If you delete the current one, the games on the Switch will no longer be playable. They are tied to the account.

Yes, it would have to go but it has to be the old account, but what do you mean by g-mail, as far as I know, you can only connect another Nintendo account.