Of course they are part of it! They never stopped being part of it. Orthodox Bishops stopped communing with the those bishops who commune with the Bishop of Rome because of theological disagreements, but he is still a valid Bishop!
Once bishops no longer agree on theology, they cannot commune with each other. Communion is a sing of unity, not a means of attaining one.
Disagreement does not invalidate Holy Orders. If the Holy Mysteries are the kept, as is the case in both Churches, then that bishop can consecrate priests and three bishops can consecrate another bishop.
The reason why Anglican orders are not recognized in the East and the West is because their sacraments (mysteries) are deficient, so while their original bishops, if any, were valid bishops, they could not consecrate valid clergy to replace the existing ones, and that broke the Apostolic Succession of the Anglicans, as well as other Protestants.
Thanks, kosta50, for clearing up that one.