After working for a tandis que avec these accounts, Je pense J'ai trouvé out le reason:
They are certains subset, ou maybe derivative of le machine type accounts. Therefore they inherit this property depuis them, et depuis c'est requis for le machine type, c'est aussi requis for gMSA.
Vous pouvez check that les deux types closely match in they attribute sets. Also in tous of le TechNet documentation they juste give a simple unique value for this attribute, gmsa-name.contoso.com, juste like a machine account is having it.
Not sure why they juste didn't autogenerate it, et spare us le wondering et le typing.
