We don't know, but it's safe to expect a wait. Back when EA confirmed what we then thought of as Skate 4, it was clear that the sequel would be a long-term project. All we had was confirmation that it exists, and news that a new studio was being spun up to work on the skatequel. Still, back in 2021, EA teased that the new Skate was coming "soon", with CEO Patrick Wilson namedropping Skate in a question about user-generated content.
Full Circle, the new EA studio handling the new Skate game's development, acknowledged the game's still being worked on with a release of some dev footage. While there wasn't any mention of a release date, there's now a closed beta sign-up on the Skate website. If you're lucky, you might be able to get your hands on it before the rest of us.