I haven't seen much evidence of Bill W ever claiming any science to what he did, nor any of his followers doing said-same. AA has always had a spiritual framework and owes a lot more to Dale Carnegie than Freud or Erickson.
It's also clumsy and dishonest to conflate AA with "rehab." Although there is overlap, rehabilitation is a broad category of treatments and services applied to a panoply of ills through countless modalities. AA is a rigid, structured, controlled hierarchy of talk therapies applied by a semi-gnostic central organization.
I mean, the damn article lists the twelve steps. Of those twelve, four of them name-check God and two more allude to him. Accusing AA of "pseudoscience" is disingenuous in the extreme.