So what? That is not going to stop me and others from translating it. Also, if xcom was able to be ported to the playstation with japanese characters Openxcom can do it with enough effort.
Sure it won't stop you. You could even make png with 10000 glyphs, but it still won't be integrated into OXC.
Reasons:
1. There's no modular font concept implemented. YET. You can only replace, not ADD your fonts to the package (so there are 0 chances for that to be integrated, like it was with Thai, or Japanese).
2. Font size and UI is still not moddable. Japanese PSX version had reworked UI and font drawing algorithms, specially for glyphic language, and it won't work for other languages.
3. You can make your own branch of OXC git, and make that alternative version. But it won't be official and you gonna be constantly updating it and releasing alternative EXEs, like "OpenXcom Extended".
Why all this? I think it's because UI guy from oxc dev team didn't implement that modular font concept. YET.
But you can ask him. And I totally support that.