I don't know if that's going to be a whole new land, but I would guess so. More information will come later. Immersive Super Hero Experience Coming to Disney California Adventure Park
I'm surprised they didn't do more to clarify where this will go. There were rumors of using the remains of the Timon parking lot behind TOT, taking over most of Hollywoodland and the soon-to-be-relocated transit plaza north of that area, and even redoing a bug's land. This doesn't really tell us where it will be, but at least we have some general ideas of what the content will be If Disney wants to build a Spider-Man attraction, they'll have to make sure it's better than the one at Islands of Adventure. That was a gamechanger when it opened (nearly 20 years ago) similar to Indiana Jones at DL, so whatever they do will have to be really great to outshine something that a lot of people consider one of the best attractions in the world
Announcements given out in bits and pieces over a long period of time is how publicity goes these days. Waiting on the location gets media to write yet another story on the project when they do announce it.