I'll say that Dragonlance, as the results of one of D&D's official surveys say, fell into 2nd-tier popularity with Greyhawk and Spelljammer. Greyhawk has gotten a book released with GoS, and people believe Spelljammer is on its way (those are just theories though), so the possibility of a Dragonlance book is not impossible, just not very likely.
I think it comes out after than Dark Sun, barring some anniversary or media tie-in.I think Dragonlance is coming, but not next year.
I think it comes out after than Dark Sun, barring some anniversary or media tie-in.
My own forecast is:
We will see the remake of the module House on the Gryphon Hill, and maybe later the six modules about the grand conjunction in one book. The next step would be more modules set in some island of the terror.
I wouldn't rule out a media tie-in by any means.
We have to remember the gothic Earth from "Masque of the Red Death" is canon in D&D multiverse, because Maligno, the marionette lord of Odiare is from Italy. (I have imagined sometime this lord creating a squad of doll half-golems) If there is an official crossover between Ravenloft and Gothic Earth we should be really careful about some matters. Maybe in my own gothic Earth cursed monsters can go to water sources in Lourdes to be healed, and if I am the DM this works, and "Blood Mary" was a vampire-hunter heroine who tried to save her land against secret lodges ruled by vampire clans.
The shadowfell domains were canon in 4th. There weren't really within the demiplane of the dread, but they could be useful for softer stories of gothic horror. Let's imagine Shadow domains ruled by fiendish or catastrophic dragons.
* The cult of Elder Elemental Eye could be an interesting antagonist faction in Ravenloft, a place with enough madness and nihilism (and cultists with para-elemental symbiont grafts) Obyrith cults also could be a challenge for PCs and even for Darklords.
Interesting catch, I did not know that about Odiare. I will say that "canon" is an extremely dodgy term for D&D, as "official canon" changes from edition to edition; something that was true in a previous edition means little compared to the current 5e. Dark Sun for example had a series of books detailing many of the fates of the Sorceror Kings, but in 4e almost all of Dark Sun's events were reset back to only a single module remaining "history."
I'll also say I find it extremely doubtful you'll see anything like Masque of the Red Death in an official 5e book (at least in the near future). The last time it was released was by White Wolf Gaming, and for d20 not D&D. That setting would require a lot more rules, possibly more than a setting like Dark Sun, Dragonlance or something else.
Domains of Dread did some soft shifts in continuity to make every setting (that was in print by TSR at the time) have a Ravenloft darklord. Usually, there were smaller domains (from Darklords, Islands of Terror, or the like) that got retro-fitted as coming from Birthright, Mystara, or (most surprisingly) Gothic Earth. Aside from some interesting facts and possible 'this domain is like home" element, there is very little these additions added.
(As an aside, I'm not a giagantic fan of the "this domain is a dark version of [insert campaign settting]" domains, even the OG ones like Sithicus. It felt lazy, esp when actual villains (like Vecna, Soth, and Kas) were made darklords. Like, why would the Dark Powers grab Vecna or Soth but not Orcus or Accerack? But I digress...)
That said, I think MotRD 5e would be an amazing product (I've tried working on a home conversion several times myself) but it is a massive project to get right; its not as easy as putting paladins or gnomes into 1890's clothing and calling it done. It probably would require a massive re-write of classes, backgrounds, combat (for firearms), and then all the gothic/Ravenloft changes on top. I keep hoping the DMs Guild gets around to it (there has been talk of such a project at some point) but I really doubt we'll see a full-blown Ravenloft book*, let along MotRD.
* I mean, I WANT one, but since the end of the 2e book cycle, WotC has only ever considered Ravenloft to be about Strahd and Barovia. The only official books have both been redone versions of the classic module (Expeditions and CoS) with only a few Dragon articles to expand the campaign setting. I hope I'm wrong, but I don't see WotC getting off its duff and actually even acknowledging the greater CS beyond casual references.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.