I didn't put this topic in the Advanced section, not thinking Advanced Students would need it, but then I found the attached in my 1950's book "Your first year teaching shorthand" and I thought, yes they do need to beable to read fluently.
A lot of the shorthand you write will be transcribed (if not all of it). Or at least referred to later. So, yes you will need to be able to read your notes very well.
Note the requirements for Advanced students.
"Gregg Shorthand had achieved the most extraordinary success ever attained by any system in the history of shorthand." John Robert Gregg, 1922
This instruction sounds like the reader would read exactly what was written. So if someone wrote in shorthand the incorrect outline for the word "important" as "port" but meant to write "important", they would read "port". This could also help with similar outlines.