If it was Dragonlance, there is an absolutely 0% chance that Hickman and Weis wouldn't be telling literally everyone, now that the existence of the show has been announced. So I think we can rule out Dragonlance from that. Either they'd be sulking about how they "had no input", or extremely excited to be involved. Even if they weren't allowed to name the show directly there'd be something, because both of them are extremely loud about this kind of thing.
Last I checked, the Dragons aspect of DL seems to sell well and has cultural cachet, too.
Not really the latter. The books are basically not read by people under 45. This is very easy to see if you go essentially anywhere on the internet where fantasy novels are discussed.
Shadow and Bone is pretty good proof of concept that an Eberron show could work.
It's also proof that an Eberron show wouldn't necessarily be seen as a D&D show, and Shadow & Bone is succeeding in large part because it's an incredibly popular YA with a huge under-30 audience who actively made huge efforts to make it succeed, as well as having a showrunner who is extremely invested in the property but not precious about it (a rare commodity). I think Eberron would be a harder sell, especially as to the average normie, who may be confused as to how this is a "D&D" show.
I mean, Paramount may be willing to bring an HBO-sized budget.
$15-20m a show on the first season an untested property? I don't think Paramount are quite that desperate (Amazon, maybe). I'd guess $8-10m would be a more likely range, given how they budget their SF shows. And HotD is fairly efficient rather than extravagant, so it'd be very hard to compete with them on "epic" and "dragons".
"Universe" in TV terms doesn't mean "universe" in the geek sense. It just means it's its own set of characters and settings.
The show could easily be set in Waterdeep or Phandalin, which I think is a better bet than Krynn.
I think this is the most likely scenario. Not a huge fan of the FR these days but I would very much expect WotC would prefer to keep the focus on one setting, rather than immediately buzzing off to other ones.