Season 1
Not any time in the foreseeable future. It may appear some time down the road, however.
Why may? It’s a part of the story. After Zhaitan is defeated the story moves on into season 1 and then season 2 and then HoT release.
Because Season 1 of Living World was not built with the Journal in mind, and it will take quite a bit of development to change it into something that would be able to be placed in the Journal.
The Dev Teams are working on HoT, right now, so S1 is not their priority. It is something that would like to address….some day.
They are, however (so it has been stated), providing a cut-scene-like recap of Season 1 with the release of HoT.
Nearly all of season 2 takes place in instances. What little takes place in the open world is mostly limited to following the trail of items visible to everyone or speaking to an NPC or two. In contrast, a lot of season 1 took place in the open world. In other words, more stuff like Breach/Vine.
That means, to make it available for replay would require rewriting most of the story, recording appropriate dialogue, and figuring out ways to tell the open world parts of the story. It might not sound that complicated, but the actual effort involved in considerable.
In other words, ANet needed to decide whether to focus on a new story or dedicating many of the same resources to retrofitting the old story into the current mechanics. The fact that it’s “part of the story” is, unfortunately not enough of a reason.
John Smith: “you should kill monsters, because killing monsters is awesome.”