1st - the requirement stems from this within the 9001:2015 Standard.......... "4.4.1 The organization shall establish, implement, maintain and continually improve a quality management system, including the processes needed and their interactions, in accordance with the requirements of this International Standard." You can't prove that you've "maintained" unless there is evidence present to verify it against and 90 days has been the norm almost forever, it's been disputed and I don't think ever won.
2nd - The requirement will be in the conditions of contract for the initial certification process with the CB as previously stated and anyone that doesn't agree doesn't have to enter into the contract relationship.
3rd - how does one prove effective management/control of documented information (records) without having documented information (records) to control (it's a time based process)