Brilliant Diamond & Shining Pearl have been released for the Nintendo Switch as part of Generation 8. There are very few improvements from Platinum, with the bulk of the features being carried over from Diamond & Pearl. A full list of features can be found here. Some of the more notable are the replacement of the Underground with the Grand Underground, updated Gym Leader teams, and Ramanas Park.
Do note that Game Freak did not make these games, but some workers instead oversaw ILCA, who made it instead (though Masuda, who directed it, called most of the shots).
These games can be considered remasters of Diamond & Pearl instead of remakes due to how little they changed the original games, but they have been officially marketed as remakes.
