The archive feature will generally get you the content you once had a link to. There's a couple of URL forms I recognise that'll work.
/dnd/Article links
For Article pages — ones that have /dnd/Article.aspx in the URL, like in the question — there's still a way to access them: replace the 'www' in the URL with 'archive'. So for the updates archive, you'll now need to visit this link:
If there is no 'www' and it's just in the form of http://wizards.com/dnd/example then add the 'archive' portion, to turn that domain into http://archive.wizards.com/dnd/example
/go/article links
For links of this form:
This seems to just be a shortcut or redirect to a proper article link (i.e. the format in the question). Take the bit at the end following the ?x=, which in this case is dnd/updates, and dump it on the end of the proper Article URL:
http://archive.wizards.com/dnd/Article.aspx?x=
Producing, in this case, a link to the Errata & Rules Updates page:
