The aircraft used are part of the certification of the ATO.
The requirement for aircraft used by an FTO for training to be approved is not carried forward to Part-ORA. The only requirement is for an ATO to provide to the Competent Authority "a list of aircraft to be used for training, including their group, class or type, registration, owners and category of the certificate of airworthiness, if applicable". It is, therefore, the ATO's responsibility to ensure that training aircraft meet the relevant requirements.