I’m afraid that the author of the article misunderstood the Ecumenical Patriarch. The keynote address says: “Another area where the Ecumenical Patriarchate has developed initiatives and continues to play a leading role is in the reconciliation among Christians and other religions. This area of activities by the Ecumenical Patriarchate is the target of an ongoing diabolical campaign and slander in certain circles, who claim that we supposedly betray the Orthodox faith.”
That remark seems to be directed against the Old Calendarists (who are considered schismatics), and probably against some very particular detractors of the Ecumenical Patriarch (Met. Seraphim of Piraeus comes to mind) within the Church of Greece (who are nevertheless in good standing with the Church and neither schismatics nor heretics, since they do not break union with the EP over his perceived shortcomings). The likelihood that it is directed against the entire Russian Orthodox Church to me seems very slim, considering that the Russian Orthodox Church does not oppose ecumenism outright (otherwise it would not have a bishop officially placed in charge of ecumenical relations), nor does it accuse (to my knowledge at least) His All-Holiness of “betray[ing] the Orthodox faith.”