But as for new players, there hasn’t been a setting presented as in the early days of a Great War, nor a setting defined by dragons, nor a setting defined by Cosmic Balance, nor one where gods may be absent at the start of a campaign or you can just play a whole campaign with no gods or divine magic. Just off the dome.
You're going too deep into this and not thinking on a marketting level. Look at what's out there already, they're two word thing. Elevator pitch these
FR: Basic, Medieval
Eberron: Weird, Magipunk
Ravnica: Guilds, Megacity, MtG
Acq Incorporated and Rick & Morty: Comedy, draws in fans of the series
Wildemont: Critical Role
Theros: Ancient Greece, MtG
These are all vastly different themes and are scattergunning that audience appeal, grabbing different folks. Someone doesn't care for Eberron? Grab 'em with Ravenloft. Not a fan of Ravnica? Well, have they heard about the biggest D&D stream on Twitch and the book you can buy for it?
Elevator pitch Dragonlance to me and explain why how this is drawing more people. I am marketting manager and you've got me in the elevator as I head off to get my morning coffee and you've got minimum time to sell me on this and why I should prioritise it above anything else. What untapped market are we drawing in?
Eberron is literately on the cusp of a great war, so I'm not buying that early days of a great war thing given that's one of Eberron's themes.
Is Dragonlance defined by dragons? Eh, not really, its moreso defined by its heroes, plus, D&D already has a product that is "Hey look, dragons!". Its called Rise of Tiamat. I'm just saying, what most people remember from DL is its characters, not that it had dragons in there. Also do consider Dragonlance was the 'this setting has dragons!' setting in an age back in 2E, and nowerdays when you have Dragonborn as a pretty common playable race its probably a lot less of a pull than it was (unless we're talking council of wyrms because I continuing hoping that gets a revival even though I know it won't)
I'm not aware of any big communities who's thing is "Only reads stories dealing with cosmic balance" so I'm questioning on this being a sell, and, additionally, given how Dragonlance is, I'd honestly say is a negative at this point in time given how they're going with removing alignment. Plus, Dragonlance handles this... Poorly. You know how Ravenloft went, right? Dragonlance's ham-fisted approach to good versus evil gets debates to this day, when its not an actively produced book. It will stir contorversy like no one's business if they release a Dragonlance book
Eberron once again does the "Gods may be absent" thing
Beyond that, DL can be presented as a Romantic Fantasy setting, and a Romantic Fantasy world with war looming over it is not something 5e has done anything like. Beyond that, DL is a perfect time to introduce mass combat rules, subclasses for knightly orders, variant Spellcasting rules, rules for aerial combat, etc.
While an approach, it runs into the issue that this is hitting on that same "Here is western fantasy" thing. Nothing about FR prevents this type of thing and you're effectively competing against yourself with this
The ideas folks have for 'Do an Indian setting' jump out because they're new, fresh, and don't tread across the same ground. Rise of Tiamat and its reception is basically the same ground that Dragonlance will tread, except this time its a different world and you'll probably want to kill the gods and shatter their thrones by the end of it
I don’t think that actually matters, tbh.
If it didn't matter, then why do we have such vastly different settings thus far and not just retro ones? Companies want to bring new people into the hobby, and you don't do that by appealing just to nostalgia