Not so. Your post reflects an overly-simplistic view of what Basil (and other fathers) taught about baptism, as well as the bishops at Trullo.
In the Orthodox Church, a consistent position on the reception of those baptized in other communions is much more difficult, though not impossible, to discern. On the one hand, since the Council in Trullo (692), the canonical collections authoritative in Orthodoxy have included the enactments of third-century North African councils presided over by Cyprian of Carthage, as well as the important late-fourth-century Eastern collection, The Apostolic Canons. Cyprian’s position, supported by his contemporary bishop Firmilian of Caesaraea in Cappadocia, was that salvation and grace are not mediated by schismatic communities, so that baptism administered outside the universal apostolic communion is simply invalid as an act of Christian initiation, deprived of the life-giving Spirit (see Cyprian, Epp. 69.7; 71.1; 73.2; 75.17, 22-25). Influential as it was to be, Cyprian and Firmilian both acknowledge that their position on baptism is a relatively new one, forged probably in the 230s to deal with the extraordinary new challenges presented by Christian sectarianism in an age of persecution, but following logically from a clear sense of the Church’s boundaries. The Apostolic Canons, included in the larger Apostolic Constitutions and probably representative of Church discipline in Syria during the 380s, identifies sacraments celebrated by “heretics” as illegitimate (can. 45 [46]), although it is not clear in what sense the word “heretic” is being used; the following canon brands it as equally sacrilegious for a bishop or presbyter to rebaptize someone who is already truly baptized, and to recognize the baptism of “someone who has been polluted by the ungodly.” Both Cyprian and the Apostolic Canons, in any case, draw a sharp line between the authentic visible Church and every other group which exists outside its boundaries, and accords no value whatever to the rites of those “outside.” On the other hand, continuing Eastern practice from at least the fourth century has followed a more nuanced position. This position is reflected in Basil of Caesarea’s First Canonical Epistle (Ep. 188, dated 374), addressed to Amphilochius of Iconium, which–claiming to follow the practice of “the ancients”–distinguishes among three types of groups “outside” the Church: heretics, “who differ with regard to faith in God;” schismatics, who are separated from the body of the Church “for some ecclesiastical reasons and differ from other [Christians] on questions that can be resolved;” and “parasynagogues,” or dissidents who have formed rival communities simply in opposition to legitimate authority (Ep. 188.1). Only in the case of heretics in the strict sense—those with a different understanding of God, among whom Basil includes Manichaeans, Gnostics, and Marcionites–is baptism required for entry into communion with the Church. Concerning the second and third groups, Basil declares that they are still “of the Church,” and as such are to be admitted into full communion without baptism. This policy is also reflected in Canon 95 of the Council in Trullo, which distinguishes between “Severians” (i.e., non-Chalcedonians) and Nestorians, who are to be received by confession of faith; schismatics, who are to be received by chrismation; and heretics, who alone require baptism. Thus, in spite of the solemn rulings of the Fifth and Sixth Ecumenical Councils against their christological positions, “Severians” and Nestorians are clearly reckoned as still “of the Church,” and seem to be understood in Basil’s category of “parasynagogues;” their baptisms are thus understood–to use scholastic language–as valid, if perhaps illicit.
usccb.org/beliefs-and-teachings/ecumenical-and-interreligious/ecumenical/orthodox/baptism-and-sacramental-economy.cfm
