Stellar Blade developer Shift Up has teased some sort of update or piece of news it will be revealing next week with the simple tweet reading: "Get ready for next week." In the background is what looks like a statue, so the tease may well be related to merchandise rather than in-game content. Still, the team has gone on record stating it has title updates in the works, one of which is a boss rush mode — and, without spoiling anything, the enemy in the picture is indeed a boss.
Should the news relate to new in-game content, the aforementioned boss rush mode seems like a likely candidate, and new Outfits will always be appreciated by the fanbase. There's also a crossover with Shift Up's previous game NIKKE: Goddess of Victory confirmed to be in production, which the update could relate to.