In a statement, the company said, "This is true. As the game is now, you cannot create friend lobbies online. You can only play online with randoms. You can still get friends together and play with local play, and you’re free to play with four players on one Nintendo Switch system. You can also still challenge your friends to your creations and take on their designs through Course IDs and having them follow your Maker profile."
This highlights a large problem with the Switch online system (which people now pay for). The current friend code system allows players to add others to a list, and while it is currently impossible to communicate with others in games (save Splatoon 2 via app and Fortnite), most games allow online play between friends.
NintendoWorldReport notes that the integrity of online leaderboards may have led to the decision, as randomization will allow fair rankings.
Upon hearing this news, fans voiced their profound disappointment online.