Oral proceedings may take place even if they were not requested, as according to Art. 116(1) EPC oral proceedings shall take place at the instance of the EPO if it considers this to be expedient.
Source: http://www.epo.org/law-practice/legal-texts/html/caselaw/2019/e/clr_iii_c_3.htm
Date retrieved: 17 May 2021