Nope nope nope, I would write a complaint if I were you because this isn't on.
On the face of it I'm sure it is framed as a helpful way to accomodate people.
In reality, how is declaring your neurodivergence helpful? It doesn't indicate what each individuals needs actually are.
Not everyone with ADHD, autism or OCD has the exact same needs, even people with the same diagnoses have completely separate and differing needs.
All this is doing is branding people so others know who to avoid, and ableism is rife within workplaces, internalised or externalised.
Not everyone with a ND condition will have the experience or wisdom to realise that outing yourself will lead to negative interactions either, but an employer should be wholly aware of discrimination and be putting practices in place to prevent discrimination, which this is the complete opposite.
Medical information is also supposed to be confidential. Your employer should be working with individuals strictly confidentially, and instead is employing lazy practices so they don't have to do the leg work.