I think Adding Fulfilling Outside and Inside (Abyssea) content in the future would be getting the best of both worlds.

Each one offering their own Aspects. Inside-Abyssea content for ~99 Could focus on Upgrading Empyrean Weapons/Empyrean Armor. Perhaps Abyssea-Bastok/Sandy/Windurst. They wouldn't need to contain a lot, Just a few NMs that could drop Armor like the level 80~+ RSE, as well as the Empyrean Weapons upgrade items.

While out-side Abyssea content could focus on New End-game Events and new Armors/Weapons/upgrades/Etc, Back to the good old days of Dragging along 17 other people who want to lot the same stuff as you, and spending 2 years on the same event simply because the one guy hasn't gotten the 0.005% Drop of that 1 NM. you know, Challenge!