Considering Wizards seems to like turning their settings for Magic the Gathering into D&D source books, what setting from MTG would you want to see turned into a fuller source book like Ravnica and(to a lesser extent) Strixhaven? Personally, I really, really want to see Eldraine turned into a book! I love almost everything about it, from it's kingdoms and magical traditions, to the fairytale vibe of its stories. Exploring as knights on quests, engaging with fairies, giants and witches. I think it seems perfect.

I’d actually really like to see Lorwyn and Shadowmoor done as a setting book, as not only do I think it’s a strange and unique place but it would be great inspiration for those who want material for their own Feywild and Shadowfell or other planes of a similar sort.

I don’t know much Magic lore, but these have been floating around for a while.  Less detailed than a sourcebook, but they have stuff worth stealing, IMO.

https://mtg.fandom.com/wiki/Plane_Shift

I think Innistrad would make a great setting for a D&D campaign but I don't think it's very likely because we already have Ravenloft for the gothic horror niche. For those unfamiliar, Innistrad has a lot of Germanic and central European flavor, heavily features werewolves and vampires, demonic cults, and necromantic "stitchers" creat Frankenstein-esque super zombies. Those forces these are opposed by a host of angels who support human knights and other "warriors of the faith" type soldiers that fight to preserve humanity in a world full of things that want to kill, consume, and corrupt them. A descroption I'm fond of concerning when the Eldrazi invaded Innistrad goes something like "This is a world so full of terrible things that when a peasant farmer finds out that they're being attacked by humongous world devouring eldritch abominations from beyond space and time their response is, 'Mabel, get my big axe. It's going to be one of those days.'"

Kamigawa could be cool. Especially with the current Kamigawa set that's all cyberpunk and neon.

Dude you have no idea how much I want D&D to actually explore making a cyberpunk or urban fantasy book or setting.

I am kind of surprised kaldheim wasn't on the table as there has been a least one third party (two if you count Midgard from kobald press) settings with a norse theme. If I recall correctly there were at least 3 different greek inspired setting going on a year or two ago on kickstarter and then Theros happened.

Oh yeah you are right, that's another one I'd be really happy for. Though I do think, at least from what lore I know, Eldraine is a bit more structured. I can imagine adventures in Eldraine more, while Kaldheim seems like some work would need to be done to flesh it out more.