Yep, we finally have our day one online functionality of the Nintendo Switch and can confirm that the main way to add friends will be using Friend Codes.
The options in the Add Friend menu are:
- Search for Local Users
- Search for Users YOu’ve Played With
- Search with Friend Code (12 digit)
- Sent Friend Requests
You can also add friends from Super Mario Run and Miitomo, which I’ve tested and it does work quite well.