Old flying is barely even a gameplay element. It's a button to remove gameplay and reduce open world exploration to its most basic version, as in you move completely free from restrictions, away from danger, and with none of the actual moment to moment gameplay offered by other movement options.
Flying has lacked any actual gameplay ever since it was added in TBC, and it's clear that Blizzard has been in a constant battle to actually prevent it from just making the open world gameplay collapse in on itself.
They tried to make the zone larger in Cata, didn't work.
They tried making the endgame questing areas in elevated areas, didn't work.
They tried removing flight entirely in WoD, didn't work because they didn't have open world content worth mentioning.
In Legion they finally managed to get open world content to work, and they did so by not having flying.
DF is adding Dragonriding to try to give a new version of flying that can actually enhance gameplay, and not just reduce it.
Besides, everyone seems to love it, so unless Blizzard shits the bed with its implementation, then I imagine it will be carried forwards, and likely even expanded on.
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There are some visual elements. The gryphons on the side of the action bar are still there, even if they look a bit different.
Personally i think my biggest gripe are the UI elements in the bottom right corner (dungeon journal, collections, etc.)
Feels like they are likely to just disappear into the background without any defining coloration to make them visible at a glance.