Status: IN
Factory Method's status as the sole inheritance-legitimate creational gateway is reinforced by the practitioner system's confinement of inheritance to exactly two architectural roles (Template Method bridging and Visitor type governance) — Factory Method channels creation through Template Method (one of only two sanctioned inheritance roles), making it not just the sole creational inheritance gateway but necessarily so, since no other inheritance role in the system can serve creational type-selection.
Factory Method's creational inheritance gateway is necessarily sole because it channels through one of only two system-legitimate inheritance roles
Depends on (SL): factory-method-sole-creational-gateway-in-validated-system, practitioner-system-inherits-bounded-inheritance-and-convergent-validation