Before 1.1.0, "Online Mariothon" was a joke—just a selection of 10 mini-games with no board.
Yes. On Ryujinx (the current best option post-Yuzu), simply load the base NSP, then go to File → Install Firmware/Update → Select the NSP. Ensure your firmware keys are up to date (version 17.0.0+). super mario party switch nsp update 110