If I tried to transcribe my notes from every meeting, I would end up working on it for more time than the actual meeting took at this point.
I have thought about the exact same app actually. Being able to photograph my Gregg outlines and get an English transcription would be the dream.
Gregg and many other shorthands are purely phonetic. There's no difference between to, too, and two. You would need to do OCR on the outlines, map those to sounds, and map the sounds to possible words, then assemble a meaningful sentence based on what meanings make sense in context. A neural net could probably do a good job of mapping from outlines to possible words, and you could use NLP tools to try to choose a sentence from the possible outputs. It would be tricky to do well, for sure.
For now, it's vim for my meeting notes :)
You need something easy for a human to write and easy for a computer to decode.
I think Gregg is out for this reason, but so is graffiti (it's not fast enough right?).