If this becomes a regular thing, that's cool.
http://www.nintendoworldreport.com/news/69357/nso-update-monday-tetris-nes-release-date-and-more-splatoon-for-nintendo-music
As happened last week Monday has given a couple of news items for basic Nintendo Switch Online subscribers.
Following the reveal in August's Partner Showcase, Nintendo has given a "December 12th" (usually meaning the night of the 11th for North America) date for the NES version of Tetris being added to the NSO library. One of the more popular console ports of the classic puzzler, it was announced alongside last month's Tetris Forever.
Nintendo Music has also added the Splatoon 2 soundtrack to Nintendo Music today. Notably, one of the included playlists is for the Splatoon 2 Octo Expansion, while Splatoon 3's selections do not include the Side Order DLC.