Switch firmware updates seem to support some kind of "mouse mode"

https://switchbrew.org/wiki/HID_services

Relevant entries:

[19.0.0+] AddMouseWheelDelta

[16.0.0+] ActivateDebugMouse

[16.0.0+] SetDebugMouseAutoPilotState

[16.0.0+] UnsetDebugMouseAutoPilotState

Before you say "these are clearly just for Switch 1 devkits", keep in mind that 16.0.0 released in February 2023 and 19.0.0 released in October 2024. Those devkits would have had that functionality ages ago. What this suggests is some new functionality, in line with previous rumors about mouse functionality and scrolling shoulder buttons.