We can all miss out lines when reading, and that creates problems with understanding, to say the least. But it seems logical that dyslexic individuals would do it more often.
But the honest answer is that in the earlier work in 2000, this was not one of the questions which came up as highly predictive. That said, there were only five questions that were highly predictive. But who would believe a checklist of just five questions?
Whilst this may not be one of the most predictive questions, it can help both in terms of supporting an individual, and for self-awareness.