Steaming oysters without shucking meat v. just shucked oyster meat? Before COVID, I asked Chinese restaurants and they said they steam oyster wholly.

Some Michelin Restaurants serve cooked oysters in shells.
What are advantages and disadvantages of steaming oyster whole v. steaming just oyster meat?
How To Make Poached Oysters - Best Recipe | Charleston Magazine

DIRECTIONS: 
Shuck oysters, separating meat into one bowl and juices into another. In a heavy-bottom pot over medium heat, melt one tablespoon each of butter and truffle oil. Add shallot and garlic. Sweat until tender. Add next four ingredients. Sweat mixture for three minutes.
Add lemon and oyster juices and reduce liquid until almost dry. Remove from heat and whisk in remaining butter. Pass liquid through a sieve, pour into a small heavy-bottom pot, and heat to 135°F.  Add truffle and oysters. Poach for 10 minutes. Place oysters into shells and spoon liquid onto each.

These two recipes don't clarify if they steam oysters wholly? Or if they shucked meat first, steamed just  meat, then placed meat back into shell.
Poached Oysters and Artichokes with Champagne Cream recipe | Epicurious.com

Prepare oysters and sauce:

Pour oyster liquor into a nonreactive 8-inch heavy skillet and add Champagne, shallot, and vinegar. Bring to a boil and boil, skimming foam, until reduced to about 1/3 cup, about 5 minutes. (Reduce heat if necessary to keep from boiling over.) Pour liquid through a fine-mesh sieve into a measuring cup, pressing on and then discarding shallot. Return liquid to skillet, then add cream and oysters and cook over moderate heat, turning oysters over if not completely covered, until edges curl, about 1 minute. Remove from heat.


Poached Oysters with Pickled Cucumber and Caviar Recipe - Stephen Harris | Food &amp; Wine

Step 3    
Arrange the oyster shells on a platter. In a small skillet, simmer the oysters with their liquor over moderate heat until the edges begin to curl, 1 to 2 minutes. Transfer each oyster to a shell. Spoon some of the beurre blanc on each and top with  pickled cucumber and caviar. Serve immediately.
As long as you make certain you keep the oyster whole and you keep water/liquor form the oysters, one way or the other is more or less equivalent.
The shell, at that point is just a small dish.
Lot of high end restaurants (L'atelier Robuchon for example) will shuck the oyster and prepare them separately and then plate the dishes by placing back the prepared oysters on the cleaned shells for presentation; this help them perfectly prepare the oyster.
Lot of restaurants will also shuck the oyster and just add some ingredients directly on the shell with the oyster before steaming (or broiling)