This source is not reliable.
At least from what you have quoted it’s not very well written either, rather amateurish.
First of all these churches probably existed only since the Venetians and Genoese set up trading colonies. Any parishes that may have existed from the time of Constantine would have been following the standard liturgy of the diocese under their bishop.
Even it it was true that the existence was later than the article said, that it was in existence and was accepted, why close them?
Secondly, these were not the Pope’s parishes, they were part of the local synod, and allowed to use the Latin rite (of the time, different in some ways from the modern EF) as practiced by their native cities with permission, a type of indult. The residents of the city were bound to follow their bishop, regardless of where they were born, and their bishop was the patriarch.
But it still does not answer why at this point in time they should be closed by forced and the Eucharist desecrated. I think this has more to do with politics than doctrine.
Your quote also neglects to mention the matter of the Byzantine churches in southern Italy and Sicily. For those who are unaware, south of Naples the dominant liturgy was the Liturgy of St John Chrysostom, and the churches were under the omophor of the Patriarchate of Constantinople. The Normans conquered the territory, replaced the bishops and systematically converted the entire diocesan structure to the Latin rite.
This kind of thing happened time and again, the missions of Cyril and Methodios to Czech Republic, Slovakia and Poland were similarly converted to the Latin rite under force.
Okay I’ll verify that one. But I did a quick research and I could not find any documents that said that Slavs were forced to accept the Latin rite. Cyril and Methodious both journeyed to Rome and Pope John VIII even made Methodious Archbishop.
This is not supportable historically. I am going to have to ask you to show some better evidence than this man’s claim.
I checked some other article and they do say that the early Church used leavened bread. I think they might have based this on St Thomas’s claim that unleavened bread has always been used by the west.
Again, they were canonically part of the diocese of Constantinople, and the church has a right to regulate the liturgy as served.
That is true, but if they always been allowed to have the Latin rite?
Anyway, that is not the reason Cardinals Humbert and Frederic tried (without authority) to excommunicate the Patriarch. Cardinal Humbert was very vocal about it afterward, to the point of bragging, and for that writer to declare that ‘THIS IS WHY’ is not being completely honest about the affair.
This is why, in Cardinal Humbert’s own words (translated to modern English, of course

):
*]…they sell the gift of God
*]…they castrate their guests
*]…they rebaptize those already baptized in the name of the holy Trinity, and especially Latins
*]…they claim that with the exception of the Greek Church, the Church of Christ and baptism has perished from the world
*]…they allow and defend the carnal marriages of the ministers of the sacred altar
*]…they say that the law of Moses is accursed
*]…they cut off the procession of the Holy Spirit from the Son
*]…they state that leave is ensouled (animatum)
*]…they preserve the carnal cleanness of the Jews to such an extent that they refuse to baptize dying babies before eight days after birth
*]…they refuse to communicate with pregnant or menstruating women and they forbid them to be baptized if they are pagan
*]…they grow the hair on their head and beards, and they will not receive in communion those who tonsure their hair and shave their beards following the decreed practice of the Roman Church.
He also had these things to say about the patriarch (his ecclesiastical superior) …
Let them be anathema Maranatha with the Simoniacs, Valesians, Arians, Donatists, Nicolaitists, Severians, Pneumatomachoi, Manichaeans, Nazarenes, and all the
heretics — nay, with the devil himself and his angels, unless they should repent.
AMEN, AMEN, AMEN.
That’s a long list of complaints, but it doesn’t mention closing churches.
I have tried to find the source of your list and I could not find it.
Can you give me a reference for this?
From what I’ve read, the legate was sent in 1053 and Michael Cerularius refused to see the legate. The built was given in July 1054. He made them wait almost a year.