There are many important things that will help a beginner to quickly learn to play guitar. In my opinion, learning to read music notation is NOT one of them. In fact, learning to read traditional music notation will only make learning to play guitar much harder and take far longer for a beginning guitar student!
Beginner guitar students need to focus their attention and learning on the physical demands of learning to play guitar and developing the relationship between these physical skills and the sound they create (ear training).
If they also focus on the demanding task of learning and memorising music notation, then the student's entire progress slows down - which leads to massive amounts of frustration with little benefit in the early years of playing.
As I say, most of my own personal guitar heroes including Angus Young, Jimmy Hendrix, Dave Grohl and Eric Clapton never learned to read music. They definitely attained a tremendous amount of skill, musicianship and practical music theory knowledge (scales and keys, etc). But, learning to read music notation is something they did not require for what they went on to do.
Of course, learning to read music notation can be a valuable skill, however it should be learned later in a student's development if required, NOT as a beginner.