For those who are only familiar with acute illness, the concept of celebrating a diagnosis is akin to celebrating being sick. But for people who have been sick for months/years/decades without a diagnosis, getting clear answers is certainly something to celebrate. It gives us and our care providers a structure of what to expect: a name, an idea of how the illness progresses, and treatment/management options.
At the same time, I think it’s important to push back against the other ways diagnosis currently functions. Your illness is real without a diagnosis. You should be able to receive accommodations and support without a diagnosis. You are not worth less for being sick.