The building inspectors job is to check that your work complies with the building regulations so from their perspective this is true.I was told that it was not available or needed as the completion certificate covered the work.
Of course filling out an EIC is advisable and may help to demonstrate to building control that your installation is compliant with the building regs but it has not and never has been a legal requirement.
Which is all that legally matters.The completion certificate only says that the work complies with Building Regulations. Including Part P - electrical safety.
Which are not and never have been law.The installation certificate states that the work complies with Wiring Regulations. (BS7671 or equivalent).