The AI first claimed there were no variants before backtracking and then dealing with the variants. That's a consistent pattern of unreliability and if you don't already know the facts then are vulnerable to accepting AI nonsense as fact. You may not care if errors are relied upon to support the truth but the God you purport to serve surely does not have such a cavalier attitude to the truth.
Even staunch Trinitarians such as Raymond Brown don't think Acts 20:28 can be relied upon. I am satisfied from my reading on the subject that at the very least there is significant doubt about what this verse really means and no doctrine should be based on it. That's a very generous assessment of the evidence. In truth I think the Trinitarian reading is extremely unlikely for the many reasons that textual and biblical scholars, including Trinitarians have outlined at length.