For me, I burned out on "keeping up with metaplot" after being a While Wolf fan, circa the Time of Thin Blood / Week of Nightmares. Most of the time it boils down to NPC's doing cooler stuff than you'll ever be able to, and bits of the setting that (at least some) people liked being blown up to raise the stakes.
I don't see the value in an "update" because from everything I've heard, the Spellplague and Sundering were straight out of a bad Marvel / DC Comics event--a huge crisis crossover that mangled the setting beyond all recognition.....followed by other creators trying to retcon the whole thing as best they can without just saying "that never happened". Because rather than trying to reverse an ill-advised setting change in-universe, I can just say that never happened or that it hasn't happened yet. We're playing in the 3e setting and period with 5e rules, the metaplot is just a possible future, now go.
Yeah, I mentioned upthread how most White Wolf fans I knew gave up on metaplot with the Reckoning (Week of Nightmares/Time of Thin blood, all the same events). I definitely get you on that being the moment most WW fans just started to walk away from the metaplot of WoD.
Yeah, the Spellplague really did seem like some bad plot twist from a comic book, like a soft reboot of a popular book to fit new trends:
They had Shar kill Mystra (and Mystra stay dead, which was the weird part, since you know, she's not supposed to be able to permanently die, even to the point that if she does die, Ao just elevates someone else to the role of Goddess of Magic), and her death caused magic to go wild (like when Mystril died during the Fall of Netheril), ravaging all of Toril for years or decades, killing most of the Faerunian pantheon, completely reshaping the map, wiping countries and cities off the map, a new continent emerges in the ocean, and 4e picks up a century later the chaos has died down to the point of it being ready for adventurers. . .and now Faerun is a Grimdark 4e "Points of Light" setting with 4e-specific elements like the Raven Queen and Primordials and Elemental Chaos and such shoehorned in. . .and then at the end of 4e they have a metaplot event spelled out in an RPGA Living Forgotten Realms module that explains why Ao couldn't stop the spellplague or revive Mystra (the forces Shar used to kill Mystra were from the Far Realm, outside Realmspace and Ao's control and even the almighty Ao was helpless to block the Far Realm incursion that cause the Spellplague, and it would take him a long time to be able to purge it from Realmspace). . .so with 5e it's my understanding that they went to Ed Greenwood and asked him to help fix the Realms that they'd broken, and they basically had Ao undo the various changes over a few years, reshaping the map back into its familiar shape, reviving the dozens of gods that were killed, rebuilding the cities that were destroyed. . .and they never were too specific about how it happened (because they didn't make a 5e Realms book yet) but now in the 5e timeline, it's about 120 years after the 3e timeline, but things are vaguely much the same as they were in 3e, except for where they aren't, but they haven't detailed what's different and what isn't.
. . .and yeah, it does sound like a comic book deciding to take on a "dark and edgy" tone under a new writer, only for it to flop and another writer to come along and try to retcon it all away. Only way it could be more of a retcon would be to have Chronomancers outright prevent it from having happened in the first place.