A learning disorder is present when a child of average (or above average) intelligence has difficulty acquiring or gathering required and specific skills.
On first reflection, therefore, the tendency would be to say, "yes," that a non-verbal child will always have a learning disorder - certainly until such time as technology allows him to verbalize - if that is possible in the circumstances. However, this question actually has no real right or wrong answer due to the number of contributing factors in determining a learning disorder. A child's surroundings and social environment will either obviate a learning disorder or distinguish and emphasize it. Academic achievement need not be affected because of a child being "non-verbal" but unfortunately, being poorly equipped to assist such a child in the education sphere may contribute to poor academic achievement.
Language-based communication dominates our society and it is clear that a "non-verbal" child will have difficulties making himself understood or potentially understanding others - depending on the environment. The term learning disorder is synonymous with learning disability and, while a non-verbal child certainly has a disability, this does not need to translate to a learning disorder.
Any difficulties experienced by a non-verbal child in acquiring communication skills do not necessarily exist due to any neurological functioning or malfunction. The origin of the disability will contribute to a determination whether any particular child will have a learning disorder together with other factors that may be present.
I think it is safe to say that no-one would claim that Helen Keller, a Harvard graduate who could neither see nor hear and who only started to really learn to speak at age nine and then only through very limited means had a learning disorder. She found other ways of communicating such as the manual alphabet - spelling letters on the hand. Despite mjor frustrations n her early life, she proved, as a largely non-verbal child, that she did not have a learning disorder!