The dev says this is one of three big announcements. One could possibly be a release date for the mobile version, but I’m not sure what the third could be.
For anyone interested in game development: Balatro is made with Love2D. Which means the exe you download from steam can be unzipped using just about any zip program (might need to change the file extension from exe to zip) and the whole source code and 2D asset files are available for perusing. Not even obfuscated, full variable names and comments available to inspect as a real world example of a working game that has sold like hotcakes because the end result is good. Let it inspire you, let it teach you :)