I can mention one deck that doesn't work as advertised anymore. The Silver PSNbow, By iancudorinmarian. Not enough PC mostly. Can be fixed by packing 2 Pulvies. Snovabows and PSNbows especially rush well.
The rest are actually a-okay despite an update being long ago. Reason being Arena changes rather every week between metas but doesn't ever take a huge leap in difference.
To add to this a little bit, all tests shown were conducted during the
current patch (1.32) so no changes to game mechanics have affected any of these tests. Metas, however, shift rather quickly, particularly in relation to the top decks for a given target.
The top decks in particular tend to take a hit because once they become known and many people play with them, decks that can beat them tend to rise through the ranks of the league while decks they beat are rapidly ejected from the arena. Along with that, people who follow the meta will tailor their submissions to beat the popular farmers.
As Higurashi noted, though, it's often possible to slightly tweak a deck to mitigate whatever counter(s) are popular in a particular league at any given time. For example, I personally love to swap a reflective shield into wrecking ball when playing silver due to the amount of sow/psion-based aether that's been around lately.
With all that being said, I rarely find the meta-related shifts to be
huge - it's usually a roughly 3-5% swing in most cases, though I've seen some top tier decks lose a good 10-15% from becoming too popular for a given target.
So, in other words, yes the information is current, but meta swings can (and do) make certain decks perform differently on any given day than they have in the past. Even meta swings don't tend to make an
enormous difference in most cases, though.