This was done under the emperor St. Constantine XI in 1452 - but the other Patriarchs had already rejected it by that time - so I give up the point, since I can't disprove that quote from the Encyclopedia. It may be a confusion from what Fr. Gill, S.J., quotes in his book on the Council:
Finally the subject of the divine essence and operation was mooted. Whereupon the Greeks took fright and replied: 'That is not for us to answer, but for the whole eastern synod', which would seem perhaps to imply that as regards the other questions discussed they had held some kind of mandate from their fellows. Of all this they gave a full report to the Emperor.
Since the Decree of Union itself declares the schism ended, and Mark of Ephesus likewise thought that such had been the intended effect of the decree.
Florence never became official and it was a coerced council with Islam slaughtering Christians and the Pope only agreeing to help through blackmail. It was the most disgusting display of Papisim which in short order create dthe conditions that gave rise to Luther.