It's incredible to me that this question still isn't solved, or the feature added! It's been invaluable since its introduction. Now that it exists, "Read Aloud" is a basic accessibility feature. It's essential for DRAFTING. Please address the return of this feature!
Reading aloud is at least available for received messages, although people don't seem happy with Immersive Reader (I have no comment, I don't use this feature). But I will say that if you want people to use your "new!" "improved!" versions of things, can you please improve them?