Thank you for the link/details. The original intent was indeed to continue supporting the same languages as D:OS 2. Unfortunately, once development had progressed to a point where there was enough finalised text to begin translating, the scope of that meant that it was not feasible to do (in D:OS 2 there were 17,600 lines of dialogue in Early Access; with BG3 there are 45,980).
After release additional localisations can be reconsidered.