The overhaul of the main ARR storyline removed 13% of quests; others revised to be simpler.
This is the absence of the overhaul of the main ARR scenario. For anyone familiar with the 2.0 to 2.5 questline, that's a substantial number of quests that simply don't exist anymore. Additionally, most of the remaining quests have been made easier to complete, although we don't yet know which ones (expect to kill fewer enemies, collect fewer items, and talk to fewer people).
To make the entire ARR MSQ a more streamlined affair, the experience points for these quests have been increased at all levels, and the rewards have also been revised to better aid progression (you'll be less likely to finding yourself below item level requirements while trying to advance the story). The goal was to allow players to push the main storyline without having to complete side quests to keep up with level and equipment requirements. ARR dungeons have received a similar overhaul: all unwanted items have been removed from chests, an experience bonus has been added for the first time, and you will now get a guaranteed piece of gear for your class after defeating the boss. final.
That said, two previous side quests were made mandatory for ARR MSQ progression. The first is the simplest: "My Little Chocobo" must be completed either before accepting "Operation Archon", or "The first flight of the Excelsior" If you have already cleared the ARR and have not yet completed Heavensward. You'll want to grab this one when it's available at level 20 - it provides you with your first mount, which makes getting around much faster.
The second requirement is “The Light of Hope,” which can be found at the end of the Crystal Tower Alliance raid quest chain. You will need it if you haven't cleared “A Time for Every Goal,” which is close to the post-ARR MSQ final. If you enjoy the story, I highly recommend that you don't deal with it as quickly as possible. The crystal tower arc plays an important role in Shadowbringers, so you'll want to be careful if you care about Final Fantasy XIV's bigger storytelling.
These are the only new requirements to complete the ARR main story revamp. As an added bonus, everyone unlocks Eorzea flight after completing "The Ultimate Weapon", so those of you who have not yet completed the 2,1-2,5 MSQ will have a much harder time complete those quests we old folks. do them all on foot. Good times, good times.
Just keep this last point in mind: if you were on one of the deleted or rearranged quests, you will be prompted to choose the next quest (if you were on a deleted quest), or to reacquire your current quest (if it has been revised). The task list and your journal will let you know if this is the case, and you will be directed to where you need to go next.