Following the latest ArcGIS Online update it seems that there have been changes to what is accepted as a service title. Previously service names could be edited to include a hyphen. However now, when trying to add a hyphen to a service name, it returns the error:
"The title of a service may only contain alphanumeric characters or underscores and be 90 characters or less."

Is there any reason why this is now being enforced? We already have many views with hyphens etc. in their names. Are these still valid?