Harsh reports are transmitted in some historical discussions concerning people who asserted the Qur’an’s createdness, but the same material raises questions about their chains of transmission, wording and attribution. Reporting a narration is not equivalent to establishing its authenticity.
Especially in theology, a disputed or judged-fabricated report must not be presented as an unquestionably authentic saying of the Prophet ﷺ. If mentioned for historical context, its evidentiary limitations should be stated.
The main doctrinal question remains what eternal divine speech is and how it relates to the created voice of a reciter. A disputed narration does not settle that conceptual issue.