It has indeed been confirmed in the last operational update:
Consistent with the undertaking given by the Governments of Australia, Malaysia and the People’s Republic of China in April last year, 120,000 square kilometres will be thoroughly searched. It is anticipated this will be completed around the middle of the year. In the absence of credible new information that leads to the identification of a specific location of the aircraft, Governments have agreed that there will be no further expansion of the search area.
Source:
https://www.atsb.gov.au/mh370-pages/...al-update.aspx