Compare the serial number with the spreadsheet before making your purchase.Any chance for the splatoon 2 bundle to contain 3.0.1 in it?
All of the switch in my local area has 3.0.1 already, and the only way to get firmware below that is by buying the splatoon 2 bundle.
Also, keep in mind that you won't be able to download Splatoon without updating the system to the latest version.