Copts and Indians still do (although the practice with the latter is varied). I'm presuming because of this that the Ethiopians and Syrians also practice individual confession.
I am not sure what Mor Ephrem meant, but the Coptic Church does not replace individual confession and getting the absolution from the mouth of the priest by any other practice for the forgiveness of sins, which is fullfilled with communion afterwards.
It is also encouraged to confess the sins at all time in front of the Lord, whether in the liturgy, in night praises, at the Agpeya prayer Hours, or at any time, in a church setting or anywhere, but this does not and cannot replace confession to the priest, one to one.
Maybe Mor Ephrem was pointing out to a historical incident. In the years of reign of the Ayyobis and Mamlok sultans, Egypt was in chaos and there was a continuous persecution of Copts, and the churches were closed for many years, or converted to mosques to mosques. In the years of Sultan Kalawoon,for example, the prevention of Coptic liturgy or prayer in churches or otherwise extended for 13 years. As such, the priests had to go from house to house to give communion, and to pray, holding individual liturgies at times. Their number was declining because they were killed if discovered. Because of the lack of time, and the lack of clergy , the Pope at one time allowed that the people say their confessions during these "hidden" liturgies while the priest holds the incense and moves around the house (church). This was an exceptional case.