I do not agree that the Church has not upheld those two councils as being on par with the First Seven, and I certainly do not think the issue is as cut-and-dry as you imply (see Pensateomnia's earlier post on the matter for some examples).
The only Orthodox support for Eight Councils comes from the 1848 reply of
some of the Orthodox Patriarchs to Pope Pius IX's letter.
There is a 1000 year gap when the idea of 8 or
even 9 Councils seems to have been unknown in the Church.
Now that one example from 1848 does not count for too much - and it is even less
substantial when one reads the letter and sees that there is internal
confusion. The letter contains:
EIGHT references to SEVEN Ecumenical Councils
TWO references to EIGHT Councils
No references to NINE Councils.
This is quite a discrepancy in the letter and those who support Eight Councils
need to account for it. They also need to account for not the slightest
mention of a Ninth Council.
Here are all the references compiled from the 1848 Encyclical:SEVEN:
"For being the miserable cogitations and devices of miserable men,
both one and the other, struck with the thunderbolt of the anathema of the
seven Ecumenical Councils, shall vanish away, though they may last a
"The new doctrine, that "the Holy Ghost proceedeth from the Father
and the Son," is contrary to the memorable declaration of our LORD,
emphatically made respecting it: which proceedeth from the Father (John xv.
26), and contrary to the universal Confession of the Catholic Church as
witnessed by the seven Ecumenical Councils.."SEVEN:
"It reproaches the Fathers of the third, fourth, fifth, sixth, and
seventh Ecumenical Councils,EIGHT:
"It was subjected to anathema, as a novelty and augmentation of the
Creed, by the eighth Ecumenical Council, congregated at Constantinople for
the pacification of the Eastern and Western Churches."EIGHT:
"by his letter to the holy Photius at the eighth Ecumenical
"But if his Holiness had sent us statements concordant and in unison
with the seven holy Ecumenical Councils.."SEVEN:
"..and by the seven Ecumenical Councils, and in obedience to the
"This same anathema the Seven Ecumenical Councils and the whole choir
of God-serving fathers pronounced..."SEVEN:
"..taught in the Gospel from the mouth of our LORD, witnessed by the
holy Apostles, by the seven sacred Ecumenical Councils, preached throughout
"The august Ecumenical Councils, those seven pillars of the house of
Wisdom, were organized in it and among us."