https://wccftech.com/pokemon-brillaint-diamond-shining-pearl-day-1-patch-ending-online-features-not-at-launch/

Day 1 patches have become the norm in the industry, with Nintendo being one of the few holdouts. Most games published by The Big N are playable without needing to connect to the internet, but it seems that won’t really be the case with the upcoming Pokémon Brilliant Diamond and Shining Pearl. The Day 1 patch for the latest Pokémon games is required in order to access online features, post-game content, and event the game’s ending cutscene. Speaking of end-game content, here’s a trailer for the Brilliant Diamond and Shining Pearl’s new “Ramanas Park” area, which will let you catch various legendary creatures.

Pokémon Brilliant Diamond & Shining Pearl Day One Update Confirmed