Some deaf with HAs were able to learn to speak and understand spoken English.
Some deaf with HAs were not able to learn to speak and not able to understand spoken English.
Some deaf with CIs were able to learn to speak and understand spoken English.
Some deaf with CIs were not able to learn to speak and not able to understand spoken English.
The key is we dont know who will benefit from which device so to safeguard against any language delays, provide ASL to all of them because all deaf children will speak and understand ASL since it is fully accessible to them.
That's the point that Deaf activities and people in the Deaf community are trying to make with these hearing people who seem to have difficulting understanding that concept.
As for the view that CIs are a person's way of shunning the Deaf community and ASL, that's a WHOLE different issue and it was probably the issue the mother in the movie had but I can only speculate since I wasnt there with the family.