Very interesting.
Of the Mario adjacent IPs, LM would best transition into Zelda as LM is all about old architecture and forests, a Zelda staple, and in addition:
- Zelda has enough thematics to make good use of that portal transition to Celestial with multiple options
- Zeldas propencity for castle towns and carnival games gives it a great excuse to have immersive side attractions.
Thing I can see being problematic, counter-arguments, alterations (assuming not further Zelda expansions anywhere else):
-Depending on what Zelda local you put here, LM fit better closer to Darkmoor than Zelda, but LM also has the attracting force of feeling like it needs to attach to its fellow Mario IPs. A conundrum, but maybe one that can be fixed.
-Zelda is an IP with much more grandeur than LM, so while I wouldn't like it, LM can plausibly finagle a fit in that corner, where in contrast I feel Zelda only just matching Mario's footprint and condensing any of Zeldas locals as proposed might be a wasted opportunity.
- To expound here's how I see the potential of your proposed layout, its well done as I can grasp a semblance of something like a cove or pass way through mountains, which certainly mimics the transitions from Hyrule Field to several locations etc. but unless I could guaranteed Zelda would also expands somewhere else it feels like it lacks the parameters for Zelda's biggest icons.
Hyrule Castle Town: Needs the Castle, needs the Town, as always forced perspective is our friend, and they've certainly done similar cramming in Mario Land, but the castle doesn't provide any big ideas for a matching E Ticket, where ideally it would be one of multiple facades for a larger land
Zoras Domain: more flexible in the constricted space, but a very odd place to have by itself, Zoras and Water rides are cool, and they'd certainly make the best transition to black lagoon, but they don't have what it takes to carry the whole brand by themselves and a water ride would need more space than this.
Death Mountain: Same thing for Gorons, too specific, with the added problem that Death mountain is one of biggest locations, and its E-ticket would beg for a mine kart/lava theme stepping on DKs toes with another small coaster unbefitting its premise.
Temple of Time: Okay, this one actually fits the footprint and has an magical and godly excuse for having a smaller simulator ride, It facade could matches both LM and Darkmoor if done correctly, and while the ride would need creativity its would also be the most flexible, making this is one of the better options
Hyrule Field: Best saved for a mural as some other location's horizon wall, unless there was an entire Theme Park designated to Zelda, Lon Lon Ranch and empty grasslands are too big for what they provide, we go to the county fair for much cheaper if we have a hankering for horses
Lake Hylia: Same, best leave fishing to the real lakes out in the world
Kakariko: At first glance the most likely icon to fit at the cost of having nothing to base an E-attraction on, except that is merely a ruse because they could go real hard on this given they have a ginormous excuse to have this land secretly be the Dark Temple under the Kakariko Graveyard/well, making an excuse for an elevated land with deep basements, basements they'll want anyway across the expansion for LM to support and expand both rides, but also being a huge flavor synergy together and with Darkmoor next door. This would be the first idea I feel like where it would be worth it to not just let LM have the whole plot and put all of Zelda somewhere else, and that makes it my favorite to win!
Gerudo Desert: Any excuse for Gerudo Cosplayers is great but bandits and Desert cliffsides aren't exactly the most fun place to be, and like the other races, a bit too specific for Zeldas first land, and lesser E-ticket potential because there's no room to have wide open sands and a spirit temple for that mummy connection to monsters.
Deku Tree: Kokiri Village has one of the best excuses for being small and hallway like with various side attractions, Koroks (and pikmin) would likely be incorporate heavily here for cute mascot bait, the Lost Woods make for a wonderful trnasition and sountrack for the land from celestial and into LM. and Finall the DK Tree has content for a cool E ticket while also be a Location with big excuses to have tower-esque ride building, once again with a basement. The 2nd best option IMO you could put here if you had to.
I'm not saying by contrast a Zelda expansion where it didn't have to share would fit everything, but much more than Mario, DK, or LM that don't have such a wonderful breadth of locals, I would certainly want more than one with a focus on covering the most ground possible. SO even with the best options here, I'd still kinda want Zelda to have its own big World.