The only part of Atom that’s seen any significant work on features in the last couple of years is the git/github extension. AFAICT most (if not all) of Atom’s core devs have moved on to other projects. As the commit graph shows, this isn’t really a new development.
Now, as for what this means for Juno: We’ll definitely keep supporting the current Atom-based plugins for the foreseeable future, but a switch to VSCode is becoming more and more likely.