I'm sure it could, its just that GF's design philosophy is totally different in SwSh than in DP, with the philosophy being currently is: " Streamline the game because kid's don't have the attention span for complex games due to mobile games. "I'm not even sure if it could fit on a cartridge.
I would not comment on this until the DLC actually comes out and gets reviewed.We're already seeing signs of this with the DLCs, both of which are boasted to add areas bigger and more content-filled than the Wild Area (admittedly not the highest bar but an improvement nonetheless).
I think the problem with ORAS is that it seems to be " Ruby and Sapphire " remake, not an Emerald remake. What I mean by this is that you have the Battle Frontier as the most glaring example, but you have things like no gym leader rematches, characters like Juan, Frontier Brains, and Scott missing, as well as story events like Steven being champion instead of Wallace. I think the former one is the most baffling, since rematches of gym leaders were in XY. In contrast, HGSS managed to keep Eusine as well as the Suicune plot while also incorporating on elements of the regular GS so it feels like you get a taste of all 3.ORAS and Let's Go were both well-loved, the former is the best-selling remake by a good 2 million copies and the latter is widely credited by many casual fans for getting them back into the series and just generally being super duper fun, and we all know how people can't get enough of HGSS)
And finally, I think there is a major reason people are forgetting why remakes are made in the first place. Remakes are often made with the intention of allowing all Pokemon being caught without the aid of previous hardware. FRLG were made because they allowed you to catch Kanto Pokemon while RS allowed you to obtain Hoenn Pokemon while Colsseum allowed you to obtain Johto Pokemon.
HGSS, in addition to allowing you to obtain John and Kanto Pokemon, also includes Hoenn Legendary Pokemon and starters because Developers wanted to remove reliance on GBA games for completing the Pokedex.
Between ORAS and XY, every Pokemon that is not a mythical can be caught via collaboration with all 4 games.
With Dexit, Sword and Shield will never have to rely on another pair of Pokemon games to complete the Pokedex. And this might be unpopular opinion, but I believe that was the primary reason why the remakes were made in development in the first place, as well as to make money off nostalgia and save time off on development by reusing maps and characters.