Blizzard changed the leveling experience at the same time those new characters became available. It used the scaling tech available in its later zones to make broad swaths of older areas available to a much wider level range, so that characters could choose what quests or zones they wanted to do and stay there, rather than out-leveling them too quickly.
While the expansion kicks off with heavy references and scenes of this war, leveling through the Horde side of the new content it barely came up again. Except for all the times I had to mine Azerite to make sure my faction was the leader in the Azeroth version of a nuclear arms race. The Alliance side of things had some heavier references to to the war, at least in the portions I played, with one scenario in Stormsong Valley where a fleet of Horde aggressors bombed a town.
It's not an enchantment, but you should buy or craft an iLVL 100+ belt, gloves, or boots with a gem socket for use with the new 5% bonus experience gem: Insightful Rubellite. I used a vendor-bought belt from the legacy valor vendor in Orgrimmar, since it was convenient and met the minimum ilvl bonus. Keep these in your bags until you can equip them, which should be just in time for treasure collections in WoD content. I didn't ever replace the belt until I dinged 110, since I didn't feel the stats from later upgraded belt drops made enough of a difference to outweigh the 5% bonus. This is explained below, in the WoD treasure section.
Galakrond-Alliance-USGalakrond-H-USGarithos-Alliance-USGarithos-Horde-USGarona-Alliance-USGarona-Horde-USGarrosh-Alliance-USGarrosh-Horde-USGhostlands-Alliance-USGhostlands-Horde-USGilneas-Alliance-USGilneas-Horde-USGnomeregan-Alliance-USGnomeregan-Horde-USGorefiend-Alliance-USGorefiend-Horde-USGorgonnash-Alliance-USGorgonnash-Horde-USGreymane-Alliance-USGreymane-Horde-USGrizzly Hills-Alliance-USGrizzly Hills-Horde-USGul'dan-Alliance-USGul'dan-Horde-USGundrak-Alliance-USGundrak-Horde-USGurubashi-Alliance-USGurubashi-Horde-USGallywix-Alliance-USGallywix-Horde-USGoldrinn-Alliance-USGoldrinn-Horde-US