Great and welcome news. Ian confirmed during a Blizzcon interview that flying will not be available in Battle for Azeroth at launch. Furthermore, Blizzard will continue with this approach for the foreseeable future in subsequent expansions.
https://youtu.be/DkdTS_8Y61Q?t=37m
Paraphrase of Ion's quote from the link above:
Its great to see Blizzard continue to acknowledge / listen to the community - and not cave in to a small minority of outspoken and melodramatic players who wouldnt know whats good for the game if it hit them in the face - in agreeing that World of Warcraft is a game best played and experienced on the ground. Its as simple as that.
Thankyou, Blizzard.
I think the biggest Flying lesson learnt from Legion is: the better the content, the lesser we need flying and ppl even care about it. The weaker the content (Warlords of Draenor) the more people will be frustrated and bored and grasp at things to complain about andor ways to skip content.
If Battle for Legions content is as strong as Legions (or better) - we can hopefully get away with having no flying for even longer this time round.