My son has a nintendo switch and wanted to play overwatch on it. I downloaded overwatch on his switch and logged him into my bnet account because the game required a bnet account. 2 weeks later i decided that i would like to play diablo 2 resurrection on the go, so i went out and bought my own nintendo switch and set up an account with nintendo. I bought diablo 2 resurrected for switch, loaded it up, but BAM!! You can not connect a different nintendo account to your bnet account for another 365 days. I disconnected my bnet account from my sons switch but still… 365 days before I can connect my own bnet account to my own nintendo account. Blizzard support told me there is nothing that can be done and i have to wait a year to play my game with my characters on my switch.