At some point, Zygor was destroyed. Accounts differed as to what the cause of this was and when it happened. According to one account, the planet was destroyed in the war against the Xaranti. (PROSE: The Bodysnatchers) Another account given by the Zygon Broton in the 20th century said his world was destroyed in a "recent catastrophe". (TV: Terror of the Zygons) Another account, given by Elizabeth I who had been posing as a Zygon in 1562, said that the Zygons lost their world when it burned in the first days of the Time War. (TV: The Day of the Doctor)
I have tried it a few times. It's good if you're new to the game. Otherwise not so much. I found I leveled slower by using it, as it's suggesting to take the longest possible route usually. Basically following roads everytime, when you could take an easy shortcut. Especially if the shortcut involves a bit of fall damage, it's out of question. The "go here" spots don't also update if you take a shortcut, and then the waypoint arrow points to wrong direction. But perhaps it has been updated since then.
Zygor was the home planet of the Zygons. (PROSE: The Bodysnatchers) It was known to be warmer than Earth and covered in water, which was in the form of lakes with a different mineral composition than those of Earth. There were also no icecaps on the planet. Native lifeforms of Zygor included the unaltered Skarasen and the Zygons. (TV: Terror of the Zygons)
1 All expansion guides are written in the Battle for Azeroth beta in order to have them ready on launch day. It's important to note that betas can be buggy and unstable and may delay and even halt our progress on the guides. Furthermore, the time between the start of beta and the announced release of Battle for Azeroth is much shorter (by about 2-3 months) than past betas. As a result, our primary focus is to have the Leveling guides updated by the launch, and only if those are complete and time remains will we work on updating the remaining guides. All guides not finished in beta will be updated post launch. You can read more about this here.
With the Classic beta now out it seems every related article somehow manages to spark the eternal war of "Vanilla was the best WoW sucks now" and "lol nostalgia goggles, Vanilla sucked, enjoy your two weeks of Classic". I have to say, even though I understand the principles behind the battle and the reasons people behave and talk this way... I actually REALLY don't get it on a deeper level.