Yes and no. As both I and others have said elsewhere in this tread, with the broad definition of dyslexia "students with reading troubles" who will most benefit from extra instruction have dyslexia whether they are diagnosed or not. Getting those kids properly diagnosed is therefore a better strategy because that comes with added benefits that aren't directly related to teaching like the legal protections and the internal psychological benefits I mentioned and that were mentioned in the article. Without that diagnosis, it is easy for the child and the child's peers to view it as a problem with intelligence which can be damaging mentally.