Pokemon Scarlet and Violet version 1.2.0 still doesn't have a release date more specific than the end of February, but Nintendo has released the patch notes detailing what will be featured in the update, though did note more are planned for it. In terms of feature adjustments, the main focus is on additional functionality for Pokemon Boxes. When on a Pokemon's summary, you'll now be able to change a given Pokemon's nickname, markings, held items, mark- or ribbon-related titles. You'll also be able to reorder moves, have Pokemon remember or forget moves, and use TMs.
Bug fixes for battles are mostly Pokemon specific, like one where if a Zoroark has Terastallized and is disguised as another Pokemon using its Illusion Ability, "the type matchups of moves are displayed based on the type of the Pokémon that Zoroark is disguised as, rather than Zoroark’s Tera Type.
You also won't see random Poke Balls in places they shouldn't be, and passersby won't appear on screen during certain battles that take place in towns during the main story. Importantly, the game won't forcibly close at certain locations, and as a result, you might see fewer Pokemon and people displayed in certain towns or in the wild. There are numerous other fixes coming too, not all of which are listed in the patch notes, though there's no mention of arguably the biggest issue the game faces currently: its choppy frame rate.