The revised cut-off dates (which are actually a return to those of several years ago) will be strictly applied by all schools in the UAE without exception.  Irrespective of assessment etc., there is no flexibility in this regard.  We can only suggest that you place your son in nursery if he does not already attend one, since this will enable him to develop his social and emotional skills to ready him for school.

Good schools will certainly assess your son once he begins school and will ensure that he receives the appropriate academic challenge.  There is plentiful evidence that starting school at a later age has a positive rather than negative impact.  Many countries to do not start formal education until children reach the age of six, including Australia, Germany and most Scandinavian countries.  He will not therefore be disadvantaged by waiting an additional year.