The dark void before every Nintendo Direct often becomes a breeding ground for gossip and leaks and this time is no different, as there are rumors that new 2D Metroid game and Paper Mario games are coming to the Nintendo Switch.
We already know that Metroid Prime 4 is in development for the Nintendo Switch, but that game's development was started over from scratch with Retro Studios brought back on board. The only Metroid content on the Nintendo Switch at the moment are the retro games available to Nintendo Switch Online subscribers, though there have been many rumors of an HD remaster of a Metroid Prime Trilogy in development over the past few years. Meanwhile, the most recent Paper Mario game was Paper Mario: Color Splash for the Nintendo Wii U back in 2016 and the series has been dormant ever since.
It seems that there could be more Metroid and Paper Mario games on the way. Noted leaker Sabi (who correctly leaked much of E3 2019 before it happened) has said on Twitter that a new 2D Metroid game that is related to Metroid Fusion and a new Paper Mario game will both be released in 2020.
The Nintendo 3DS received a new 2D Metroid title back in 2017 in the form of Metroid: Samus Returns, so it wouldn't be surprising for Nintendo to want another 2D title to fill in the gap created by Metroid Prime 4's delay. The Paper Mario series has also been dormant for a few years after a few mediocre titles, so the time might be right to brush the series off and try to revive the concept.
The Nintendo Switch's 2020 schedule is looking increasingly bare in terms of exclusives, especially now that Tokyo Mirage Sessions #FE Encore has been released. Nintendo has been keeping its cards close to its chest over the past few years and saving announcements for the year when the game is expected to be released, so the reveal of new Metroid and Paper Mario games that will be on store shelves in 2020 wouldn't be too surprising.
Source: Twitter