It would be nice to replicate in other languages. In Spanish and German, reading is almost phonetic, unlike English. Anyway, from my experience with my daughter, the step from single letters to silabes is difficult.
You should think "the step from single sounds to syllables", and the way to do that is to begin with the easy syllables like "tu", "mi", "el" (not unlike the multiplication or addition tables) before moving to longer ones. [And note that M alone is not "em", it has to be "m" when learning to read - a common pedagogical mistake! M + I makes "mi" not "emi", so M must be "m".] At least that's how children are taught in…
Consider, how do you read "f=ma", or "e=mc^2"? Why don't those follow the same rules? They use the same symbols as our alphabets, after all?
Or consider "do re mi" is pronounced differently from "do re me". And, amusingly, most people will not read those correctly. This doesn't rob the names of the notes as meaningless. Nor does it mean that they are not taught correctly. But you learn to interact with the symbols. Not merely transcribe them between representations.