Website review:
https://scarletviolet.pokemon.com/en-us/news/software_updates/
There will be a day 1 update for online play taking 1GB of space.
NOTES: To download the version 1.0.1 update, you will need at least 1GB of free space in your system memory or on your microSD card.
Casual battles will be available on release but the ranked modes won't.
Ranked Battles will be available starting in December 2022, and Online Competitions are slated for release sometime in spring 2023. Please wait for future announcements to learn more about when these features will launch.
https://scarletviolet.pokemon.com/en-us/news/pokemon_home/
HOME will add Battle Stadium statistics in 2023 as well, giving us more of a preview of mons in the game.
Seems like there is a section for pokemon (used with)/moves/abilities/natures/items/tera types. Also Tyranitar hasn't gotten a different ability.
Kleavor is in.
https://scarletviolet.pokemon.com/en-us/news/rotom_phone_case/
The save data bonuses this time are Rotom Phone Cases, finally giving us different dex skins again since Gen 5.
https://scarletviolet.pokemon.com/en-us/news/black_crystal_tera_raid/
"Tera Raid Battle events where you will be able to take on specific Pokémon or encounter Pokémon with specific Tera Types are in development and will make their debut sometime after the games are released."
Seems like the regular supply of raid events like SWSH will be in progress. Similarly, the feature is even called Poke Portal News. We've seen the menu earlier but this confirms that it exists from the X menu.
To encounter Pokémon featured in Tera Raid Battle events, you need to have downloaded the latest Poké Portal News. Poké Portal News will automatically download if your Nintendo Switch™ system is connected to the internet.
You can also download the latest Poké Portal news by selecting Poké Portal from the X menu, then Mystery Gift, then Check Poké Portal News. You do not need a paid Nintendo Switch Online membership to receive the latest Poké Portal News.
It seems like the Charizard will have set moves, mark, and ability, and can only be catchable once, so it's like an event where you have to catch it yourself while it's not normally encounterable.
The black crystals are said to be postgame, but others can join people hosting them.
"You’ll be able to take on Tera Raid Battles at black crystals after completing certain postgame events. However, players who haven’t completed these events may still participate in these Tera Raid Battles by joining another Trainer’s Tera Raid Battle, whether they’re in a multiplayer group or using a Link Code. "
As mentioned, marks are back, and this one is specifically for a 7-star raid boss. You can see that the Charizard is level 100 as well. Number of marks obtained may be an interesting stat to track though it's a dash in the screenshot.
The boss Charizard is also standing menacingly instead of flying idly.