You have to remember, developers close to a platform always live 6-12 months in the future, at least. (Talk to Brendan Eich about JavaScript, he's like 5 years in the future.)
What "finished" means in this context is that we've established which problems we're going to solve, and the solutions to those are well-understood. There aren't new problems that node-core is setting out to address by making changes to the binary itself.
The new hard things to tackle are above the core layer - CI, userland module documentation and discoverability, binary deployments, etc. There's quite a bit of polish and refinement to be done at the lower level, but the paths are clear at this point, as far as that goes.
What "finished" means in this context is that we've established which problems we're going to solve, and the solutions to those are well-understood. There aren't new problems that node-core is setting out to address by making changes to the binary itself.
The new hard things to tackle are above the core layer - CI, userland module documentation and discoverability, binary deployments, etc. There's quite a bit of polish and refinement to be done at the lower level, but the paths are clear at this point, as far as that goes.