An small but important clarification: the features that are stabilized will ride the trains all the way to stable in 1.30. But the ability to opt in to the Edition will not.
That’s important, because starting with 1.30 it will be possible to migrate code to use the new features while leaving it in a state that can be compiled on either Edition. Thus, we can actually start migrating some stable libraries before the Edition is fully announced to the world.