StudioMDHR's beloved Cuphead is headed to Nintendo Switch, and sometime after launch, it will be receiving an update that makes it compatible with Xbox Live. We've heard rumors of a much bigger partnership between Microsoft and Nintendo, but thus far Microsoft has yet to confirm plans for services like Game Pass and Project xCloud. However, they did confirm plans to expand the Xbox Live presence on Switch.
Speaking to a crowd at Game Developers Conference 2019, Microsoft executives announced that they intend to bring Xbox Live support to more games on Switch over time, including bringing achievements to select titles. However, they claim that they currently do not have any plans for a full Xbox Live Software Development Kit, so it sounds like this will be more of a game-by-game basis.
While discussing the features that Xbox Live will bring to iOS and Android, Microsoft displayed an image (below) of an online leader board. At the top of the list is "Mr. Switch" followed by "Mr. Xbox One" and "Demo User." This would seem to suggest that certain Switch games will be able to share their online scores across other platforms with the help of Xbox Live.
Source: Russell Holly