To be clear (as the guy behind these efforts), what was merged was a PR to let Neovim handle Ex-commands. This by itself was already pretty cool. In <200 lines of code, we were able to obtain full Ex-mode support, an aspect that had already taken 2000+ lines of code for much more limited support.

The PR for full neovim integration is the one you linked. It's more than just making it work with your existing .vimrc file: it's making it work with most vim plugins, leveraging the neovim runtime to make macros run faster, etc.