Who are the users that User Experience professionals refer to when designing the ultimate digital experience?
They have many ways to describe the user: persona are a generally widely used method to bring users alive and create stereotypes of users. But stereotypes always lack detail and the core of UX is the ability to deliver details and experiences to all user, even those not captured by persona.
I cannot remember seeing a persona of a disabled user ever, but I may just have been unlucky.
However, the issue here is not Persona.
The key issue is that too many UX professionals do UX but do not practice accessibility. These two skills are often naturally considered distinct skill set, different domains of UX, and often managed by different people, where one is the Accessibility expert, the other the UX expert, with a help from the designers and consultants.