Some disorders do have severity criteria posted on the DSM-5 web site
Bipolar II Disorder
Personality Disorder Types
Attenuated Psychotic Symptoms Syndrome
Not all of the disorders, existing, newly proposed disorders or reclassified disorders have severity criteria published on the DSM-5 site. Presumably different work groups for the DSM-5 have reported in with their proposed criteria at different times but the fact that the severity criteria are being assessed in the field trials has to mean that each of the proposed disorders have in fact had the associated severity criteria established. An article published in the American Journal of Psychiatry, Moving Toward DSM-5: The Field Trials ,confirms that the clinical field trials will include evaluation of the related severity criteria for each disorder being studied, including autism
"Formal field trials will involve the testing of between two and five specific diagnoses at any one site. The diagnoses tested at a site will depend on their relative frequency there. For example, major depressive disorder and complex somatic symptom disorder can be evaluated at a general medical clinic, but autism spectrum disorders require evaluation in a specialty psychiatric clinic specializing in these disorders. ...... At each site, a research coordinator, trained and monitored centrally, will record each successive entry to the clinic over a specific time period to provide necessary sampling weights for that site's variance in reliability and validity. DSM-IV diagnoses obtained for clinical purposes at each site will be used to place each consenting patient into either a stratum likely to be rich in a target diagnosis at that clinic or a stratum consisting of a random sample of all other diagnoses. The goal is to recruit 50 patients per stratum per site, a total of 150 to 300 patients for each diagnosis under evaluation, to have adequate power for a site-specific determination of precision. Two DSM-5-trained clinicians who are new to the patient will be assigned to conduct independent clinical interviews of the same patient at least 4 hours, but not more than 2 weeks, apart. The attending clinician will be able to observe the interviews. The interviewing clinicians will know the target diagnoses at that site but will be blinded to the stratum to which each patient is assigned and to the attending clinician's diagnosis. The interviewing clinician at each session will be provided the patient's current crosscutting assessments, conduct a clinical interview with the patient, make one or more categorical diagnoses using DSM-5 criteria, and complete associated dimensional severity ratings. [bold and underline emphases added]
The Autism Spectrum Disorder(s), including their severity criteria, are being evaluated at clinical field trials now under way and yet the severity criteria are not posted despite entreaties by the DSM-5 to check back for updates under that category. It would seem reasonable to speculate that their are reasons for this failure and that those reasons relate to the feedback received, much of it from persons who objected to Aspergers being grouped together with Autistic Disorder, with its high number of persons who are also Intellectually Disabled.
Any speculation about motives for the failure to disclose the autism spectrum disorder severity criteria is exactly that .... speculation. Unfortunately the APA has provided no real information for the public to consider as clinical field trials are underway which could impact the lives of many persons with Autism Disorders, including the 75-80% who have allegedly "co-morbid" intellectual disabilities. The public, in the midst of such an important process, a process trumpeted wide and far for its transparency and public participation, is simply left to speculate.