Core does not ship any locales, translations, fonts or other localization bits, just enough OS to run snaps or to boot a headless core image. While this would indeed be technically possible, core is already ~70MB big which is still way larger than we want it for either of the above cases.
Dont forget that every snapd install uses it so the size penalty would be for everyone not just users of these fonts …
There is work going on to allow snaps to use system fonts and alterrnatively i could imagine a “fonts” snap that shares its fonts thought the content interface to consuming app snaps.
Also … the work on “base” snaps might allow such a thing like a $distro-desktop-base snap (including core bits and fonts, themes, localization etc)