Speaking from about 2 years of experience...
Your switch is still usable online (And maybe local multiplier).
Your current updates will work but to get new updates you will have to find and download them on the internet (I cannot tell you where since it's against forum rules)
There are ways to get online but you need a computer (Mac does not work too well. Cannot speak on windows)
Personally, online with the switch is horrible. Frequent disconnects and long wait times back when I could have gone online. Don't know if it's better now.