I've discussed this before, but the structure and culture of Universal A&D has changed drastically from something that allowed fully fleshed narratives and lore in the event. Roddy, Mike, and Kim had carte blanche over the event and (more importantly) little requirement to focus on other things (like refreshed parades, expanded street show offerings, etc). While they did manage other things, the scale at which is was required pales to now. Roddy and Kim, especially, were predominately dedicated to HHN--to the extent Kim designed the bulk of the websites during the aughts in his spare time. Marketing was used as a supplemental element, that didn't have to calculate social media interactions, to do nothing more than buy ad space designed by A&D. And Marketing, in a similar manner, was a lot simpler back then.
That is no longer the structure. Charles, who is now officially working with Jason in developing/executing the HHN "vision," is ALSO responsible for direction of live entertainment in the parks. A&D influences marketing, but they're not marketing experts who understand "impressions," "views," and "SEO." And resources that don't go to maximizing those things, in a corporate since, are wildly inefficient expenditures. Which matters, because shareholders.
Can A&D and Marketing throw a page on the site that explains the common thread of the year? Sure. But then they have to figure out the common thread. They're already working on the event 18 months in advance, without focusing on a narrative and commonality. Throwing the wrinkle of a fully integrated lore into the equation complicates the process a, frankly, unnecessary degree.
What they're doing works. Fans can not like it but, even when the stories mattered, the stories were never necessary. And that's the point.
Hector and Chester's area in Dinoland USA has some of the best lore in Disney. Primeval Whirl was literally a wild-mouse retelling of Dinosaur next door. It was themed perfectly. Fans just didn't like it, so it was "unthemed."