The 35th-anniversary celebrations for the Super Mario Bros. series will include Super Mario 3D All-Stars, which may impact the chances of Nintendo 64 games coming to Switch Online in the future.
Nintendo launched the Switch Online service on September 18, 2018, following a year of delays. Switch Online is required to play multiplayer games over the Internet and for players to have cloud saves with compatible titles. The service launched with twenty NES games, which left fans dissatisfied when comparing it to similar online game passes like PS Plus and Xbox Live. Nintendo eventually sweetened the deal, by adding SNES games and the incredible Tetris 99, which is one of the best multiplayer games on the system.
The Switch Online service is entering its third year of service and fans are expecting the addition of another retro console to convince fans to re-up their subscriptions. It seemed as if the Nintendo 64 would be the next console added to Switch Online, bringing games like Super Mario 64, The Legend of Zelda: Ocarina of Time, and the original Super Smash Bros. to the Switch.
The addition of Nintendo 64 games to the Switch Online service has been complicated by the upcoming release of Super Mario 3D All-Stars for the system, as this includes a revamped version of Super Mario 64. If Nintendo is charging a premium for an updated port, then it's not going to give the original one away for free. A Nintendo 64 app to the Switch Online service wouldn't be complete without Super Mario 64, as this was the game that helped sell the original system. If Nintendo is planning a similar Zelda 3D All-Stars next year for the anniversary of that series, then it also might not want to give away Ocarina of Time and Majora's Mask for free either.
Nintendo has offered a number of incentives for Switch Online subscribers over the past few years, but there are people who will need a push to re-up. The addition of Nintendo 64 games to the Switch Online service would have been a huge incentive, but it doesn't seem realistic, based on Nintendo's upcoming schedule.
Super Mario 3D All-Stars is due to be released for Nintendo Switch on September 18, 2020.