If it is like ages past we will have to finish the storyline involving the new zone and also be exalted with the new race/faction introduced in said zone. However, keep in mind that with Legionfall it was time-gated to take between 4 to 6 weeks to get exalted because only a certain number of quests are given per day. Assuming the patch comes out May 28th-ish, you will likley be able to fly in July.
For the record, my ideas on flying tend to be widely liked, but typing it every post like this gets old so you can see it here: