The Emp gearsets for each job is the usual ho hum "Look at me! I'm <job>!", which makes the player have the iconic look of the job they're playing as at the time.
Based on Artifact and Relic gears of old, I'm going to guess SE will just keep Emp Armor as a +2 at max for the unforseeable future, since it's really more of a placeholder set (With kickass stats and ability augments), while there's certainly nicer pieces with a wider range of job usage to pick through for those who want / will put the time into it. Artifact was to get all players to look like their jobs, and helped with stats as well as defined their roles. Relic was a somewhat easy to obtain set of gear that anyone could work towards by joining a Dyna LS. Empyrean sets are usually easy to quest, or to do pickup NM shouts, making them accessible to all who wish to put the time and effort into obtaining them.
At 75, was there better gear than Relic? Yes, there was. The same will happen with Emp gear at 91+, but thems the breaks when SE designed a loot heavy game to keep the players running onward with their pockets opened.
As far as the renaming and now +2 versions of weapons, I figure SE will ultimately just rename them in the next update. You have to stop and ask yourself, "Is a weapon +3 really the same as the NQ version anymore? Or has it become a beast of it's own merit?" Also, consider how SE loves to toss in random splits and branches lately on weapons, like the Double Attack on Occ. Attack Twice weapons, or the new TP +100% weapons. I don't think they're really setting up to lock themselves into a position where they have to Orange box just yet. Orange box for +3 is the ultimate of quality, and I suspect they'll go with that for "Final Upgrades", should such a thing ever even happen. Just because the cap will finally hit 99 some day, doesn't mean they have to stop doing paths and upgrades on Magian trials.
tl;dr Iconic gear designed for all to be able to get, XI is business and SE will dangle the carrot to get us to chase after newer shinies so we pay longer.