WordPress Version 4.6 ⇥ codex.wordpress.org
Among the long list of improvements and bug fixes, highlights include the addition of Unicode 9 emoji support, a big update to the long-kludgy updating mechanism, and the removal of Open Sans from the administrator dashboard. Huzzah.
The replacement fonts for Open Sans are the default system faces for all OSes: San Francisco on Macs and iOS devices, Segoe on Windows, and Roboto on Android.
However, omitted from these updates are any changes to the typefaces used in the TinyMCE editor. So I made a plugin. It’s ridiculously lightweight and simply ensures that everything you see on the dashboard is a variant of San Francisco. If you have SF Mono installed, you’ll see that in the editor.
I probably won’t update this plugin unless I see a glaring issue, but I’ve been running it for the past month or so and it’s been fine.
On a related note, I just updated my copy of WordPress. If you spot anything wonky, please let me know.