Realms had the thing where edition changes mean a drastic change to the setting back in 2e with the Time of Troubles. Continuing that tradition for 4e clearly ended with them going too far, but I'd argue at least we knew where we stood in 4e. (5e Realms is an uncertain mess because they don't bother with setting books anymore).
No, that's still 4e. 5e was Mordenkainen's Tome of Foes, where every elf on every plane is ultimately descended from Corellon, and much like Elder Scrolls are former demigods with all elven gods coming from the most notable demigods getting named by Corellon. Where Lolth convinced every single elf and elf god to give up their innate shapeshifting and adopt static forms, thus becoming the mother of elfkind with Corellon as the father. Where Corellon got angry at Lolth for betraying his ideals and the spirits that defended her because "they argued that no entity who sprang from Corellon, no matter how rebellious, should be attacked." became drow after Lolth tried to actually kill Corellon.
So all elves are eternally reincarnating because Corellon won't let any of them except the Seldarine stay in Arvandor, except for Drow who apparently don't. Now trancing is remembering your past lives and the eladrin are the elves that went to the feywild and are thus the closest to what elves once were and the Raven Queen and shadar-kai are just a cursed evlen demigoddess and her followers. The book even goes so far as to call out Eberron's god of drow as another subordinate deity to Lolth on most worlds , implying that Lolth is still the true goddess of drow even on Eberron.
The entire thing is a mess of ideas that really belong in their own setting. But instead its implied to be Forgotten Realms lore, because that's the default setting now.