We usually don’t give any ETA regarding Ndless updates. This will unfortunately also be true for the latest OS 4.3, which is incompatible with the current Ndless revision.
Ndless will be updated as long as there will be contributors willing to spend their time for the community (see this previous post to understand how difficult it can be).
You can subscribe to the blog or to issue #48 of the GitHub project to follow the update.