AE Scripts has another script for text manipulation in After Effects, ArabicText, by Salahuddin Taha. Arabic, Hebrew, and other texts are written from right to left, but AE flows letters from left to right in the Composition panel (oddly, the Layer Name stays correct).
TextReverser, from LLoyd Alvarez fixes the flow when the letters are standalone, but broke the letter back into individuals. Arabic is cursive and has medial letterforms, and needed another approach.
Update: There's now an Animation Preset, Typewriter-RTL, that "only works with 2 keyframes that reveal the text from beginning to end."