Hey, can you indicate where in that 49-minute video he says that Eberron and Ravnica were canonically in the same Prime Material as every other D&D setting and can be reached by spelljamming? That would be interesting, since they were much more coy about D&D and Magic being in the same multiverse when the Forgotten Realms MTG set came out.
Also worth noting that video was in 2018, which was practically a different era as far as D&D at this point. (Mike Mearls was still creative director, for example.)
Here are quotes that I take from a posting on this topic that I made on June 1, 2020 (
D&D 5E - The Multiverse):
I think there has been an intentional ambiguity built in in order to retain the unique flavor of settings. For example, in preparing for
Wayfinder's Guide to Eberron, Keith Baker and Jeremy Crawford brainstormed ideas how to handle the cosmology of Eberron. In an interview with Dragon Talk published on July 25, 2018, Crawford noted that Baker came up with the idea that the dragon shards are pieces of the crystal sphere that have fallen to Eberron. There are also its own planes associated with it, but the Wizards team still conceives of Eberron as part of the same Material Plane as the others D&D worlds (e.g. Krynn, Abeir-Toril, Oerth, Athas, etc.).
Yet, in a section in
Eberron: Rising From the Last War called "Planes of Existence," Eberron is described as both "part of the Great Wheel of the multiverse" and also "fundamentally apart from the rest of the Great Wheel, sealed off from the other planes even while it's encircled by its own wheeling cosmology." That seems ambiguous.
On the other hand, in the July 25, 2018 Dragon Talk podcast (and in other podcasts where the subject of the multiverse has come up, Crawford and also Chris Perkins have reiterated this point), Crawford notes (and these are exact quotes that I am transcribing for everyone's benefit):
"I often get asked, ‘are all the worlds in the same universe [by “universe” he means “Prime Material Plane, which he says just before this],’ the official answer is ‘yes.’
“The Prime Material Plane is where all the D&D settings reside [. . .] Spelljammer was a D&D product years ago that grappled with what’s going on inside the Prime Material Plane [. . .] Spelljammer is specifically about the Prime Material Plane and how you might get from one D&D world to another.
“Let’s talk about Eberron. There was a period in D&D’s life, especially around the 3rd edition years, where this idea of all of D&D’s worlds being in one giant setting together, that idea started to go out of focus. And, you started ended up with worlds that were really shepherded and designed to be their own thing [. . .]. But again, it’s important for people to remember for the background of D&D, the original assumption in 1st edition was that the worlds were all in a multiverse together and that is also the assumption of 5th edition. And so, Eberron, in its original conception, arose in that environment when the worlds were not conceived of as having this relationship to each other.
“Keith Baker and I in the lead up to
Wayfinder’s Guide to Eberron, we had about a year ago, a real fun talk about Eberron’s relationship to the rest of the cosmology because Eberron introduces an interesting twist in that it’s not just a world, it’s also a world with a set of planes around it; it assumes an entirely different cosmology. And that posed an interesting question: like how do we reconcile this with this multiverse that all the other D&D worlds are in? Keep in mind that some of those worlds are in it but cut off, like part of the story of Dark Sun is that it is in the D&D multiverse, but because of the catastrophe is cut off from the other worlds.
“Keith and I’s [sic] discussion was really great in that we realized that this is not a hard problem to solve. In fact, it’s not a problem at all [. . .] Keith said, ‘what if the Ring [of Siberys] is a crystal sphere?’ When the Progenitors created Eberron, they wanted a world they could call their own. And they wanted more than a world, they wanted a universe they could call their own, and made a world with little planes surrounding it, with the desire of controlling something of their own.
“The story of Eberron, Keith and I realized, was that these Progenitors wanted to solve this problem by creating a world of their own: a world complete with its own planes, and then they cut it off; with the Ring of Siberys, they cut it off from the rest of the multiverse [. . .] when the shards fall, that’s the shield cracking.
“If a DM wants to explore Eberron’s relationship to the rest of the D&D multiverse, you can ask what happens when the cracks in the Ring get big enough?
Greg Tito than riffs on this and suggests that adventurers from Krynn could arrive through a crack in the Ring of Siberys (crystal sphere) and discover Eberron.
From there, they go on to discuss Ravnica as part of the Prime Material Plane of the D&D multiverse also. Crawford says the “The Prime Material Plane of the D&D multiverse can gobble up anything [. . .] we only know some of the worlds [. . .] the Prime Material Plane is vast."
When discussing other means of accessing other worlds in addition to Spelljammer, Crawford goes out of his way to specify that, because the D&D worlds are on the same plane (i.e. the Prime Material Plane), that if a character knows where he or she is going, a teleport spell can take a character from one world like Eberron or Ravnica to Abeir-Toril or Krynn or what have you: “Can I use a spell like Teleport or Teleportation Circle to get to another D&D world? The answer is ‘yes’ because all the teleportation spells require is the sigil sequence of a teleportation circle and the destination has to be on the same plane of existence [. . .] Forgotten Realms & Greyhawk are both on the Prime Material Plane, they are on the same plane of existence.”
And so forth and so on. Hopefully this is interesting food for thought.