In the trailer at 0:54, the player drops down thru a warp panel. What is that place? Did that exist in the original dp games? And did that also exist in platinum?
Yes it is in original DP games.
I'm not sure about design in platinum but it's there in diamond and pearl. I'm very sure it's the trade room. The one above Pokémon centres. You may not have any friends to trade with so not your fault.
Hope this helps.