Nope. Whether or not a council is ecumenical or not does not depend on a protestant definition, but an early Church one. It has been impossible for there to be a truly ecumenical council since the Great Schism.Jon. I am truly disappointed by this statement. I think that it is a gross simplification and would definitely lead to a misunderstanding of the actual history. Your comment would seem to imply that Trent was not a ‘truly ecumenical council’ because the Protestants were not in attendance.
orthodoxwiki.org/Ecumenical_CouncilsAn ecclesiological theory which has been popular since the time of the Slavophile philosopher Alexis Khomiakov first defined it is that ecumenicity—the idea that a particular council is of universal, infallible significance for the Church—is determined by the reception of the whole body of the Church. That is, while a particular council may declare itself to be ecumenical, it may later be regarded by the Church as being a Robber Council, that is, a council which did not declare the truth but rather heresy. Likewise, a council may properly teach the truth but not be of universal significance for the Church. Such councils are usually termed local. That a council must be “received” by the Church before it can be considered ecumenical is sometimes termed receptionism.
theopedia.com/ecumenical-councilsIn early church history, an ecumenical council was a meeting of the bishops of the whole church convened to discuss and settle matters of Church doctrine and practice.
Jon