Hi, RTL text alone is completely sufficient. The RTL UI is about localization and it is a much bigger job and from development experience of 30 years and over 7 million RTL users - it is not key at all.
But the mere appearance of Arabic or Hebrew text aligned to the left in a note with the commas reversing to the opposite side is borderline offensive sometimes to these regions.
This is just a suggestion, but Apple has 100% native support of RTL and simply switching it on will go a long way with a 1.5 billion population audience 
Full localization is not as important and can definitely wait.