three reasons:

1) While not announced, there will definitely be some changes to some of these. For example, although not mentioned, Theramore will supposedly burn, which will change the areas around it. Other changes may happen too.

2) Once you're playing pandas, will you really notice some of this now "older" stuff, or will you be looking for panda-related stuff? Really? Hmm?

3) While we wait for pandas, and are finishing up Cataclysm, you can certainly pass the time by leveling new toons or revisiting old zones, so why not do it? It's really not rushed as we are not even in Beta for MoP yet.

Indeed, these articles will be most useful when Mists has been released, for we'll all have Monks to level from 1 to 90, and it would be less a chore if some of the best stories in the game were touched on along the way.

Surely then, if we are all going to be busy leveling pandas from 1 to 90, this article should be "5 Must-do Alliance Zones to complete during mists", that way we can do these zones while we are leveling our pandas so not only is it interesting but it's useful as well. I doubt we'll have some brand new leveling path for 1 to 90 that'll allow us to bypass all questing.

Unless you count PvP and LFG.

As for the zones being changed - if that's true then fair enough, I just haven't seen anyone saying that they're changing "old" zones yet again ;P