That is for God and God alone to judge.ignatius said:Grace and Peace HandmaidenofGod,
Would it be fair to say that what they've kept still sanctifies, sister? What is common between us and the One True Church, Holy Tradition continues to sanctify because it has not been torn from that salvific root of Grace?
As we like to say in Orthodoxy, we won't say where God's grace is not, but we do know where it is.
The Eastern Orthodox Church is the One, True, Holy, Apostolic Church that was founded on Pentecost. Those groups who choose not to be in communion with her (whether they call themselves "Greek Old Calenderists" or the "Roman Catholic Church") are not part of the One, True, Church.
Do their sacraments contain the grace of God? That is for God alone to judge.
It is not for me to speak beyond that.