With the choice to start Heavensward white gear at iLvL115, mostly all gear from the ARR 50 dungeons at or below iLvL90 is now mostly useless. Everything up through Snowcloak now has no benefit to a player to gear up secondary jobs.
It does of course make sense to abridge a new players journey through ARR so they can reach the new content faster.
But with regards to secondary jobs... a Player with iLvL49 gear at level 49 will just be able to go to the Market board at 50 and buy a bunch of iLvL115 stuff and have zero need for any of that content except for the exp (which for now doesn't exist either).
Being that most of the new dungeon content is 55+, and that Blue gear is about 15 iLvLs ahead of normal white gear, there's no reason i can think of why these dozens of dungeons can't ultimately be a primary source of leveling secondary classes from 50-54.
Any Poetics Blue grade gear or 130 gear sets up nicely for up to about 54 or 55 before the higher stuff kicks in. So why not modify the stats on some of this old Darklight and so on stuff from the ARR 50 dungeons to be exclusively in the 100-130 range?
This way when players level secondary jobs there is a natural flow of going 50-54 on the dozens of ARR dungeons plus Dusk Vigil while obtaining gear that is useful.