Whiners aside (since the reasons for the site update had little to do with aesthetics and more to do scalability and moving off a dying, insecure platform) nearly all the old content is properly redirected.
As stated elsewhere, that didn't work with the Wiki pages plugin we were using since the guy that coded that didn't use content IDs. As such it's difficult to have those properly forwarded. (Also turns out that wiki had a serious security flaw, so we had to move off it ASAP.)
However if you did a simple forum search for the thread title, you find that content here:
Model S software/firmware changelog
Currently all the old wiki pages can be found here:
Wiki
I think eventually they'll just be moved to the relevant forums for what those threads are about rather than a wiki section.