The Nintendo Switch won't be adding new NES and SNES games in monthly batches anymore. Those libraries will continue to grow, but as Nintendo told Business Insider, "those releases will not adhere to a regular schedule." SNES games are the newest addition to the Nintendo Switch Online service, offering 20 games including Super Mario World and Zelda: A Link to the Past.
Nintendo Switch Won't Add NES & SNES Games Monthly Anymore - GS News Update
The Switch's NES and SNES library "will not adhere to a regular schedule."