The other reference is a well known fact that Maronites came into communion with Rome by the 12th century, but not all. Some either reverted or continued to follow the teachings of Macarius until after the Council of Florence (ended 1445). That Council's documents attest to that. The last remaining Cyprian Maronites accepted union with Rome in 1448. However, Pope Pius II's letter of 1451 suggests that even then there were some remnants who did not. Is that in dispute?
Now, raising objections as to whether a source is legitimate is valid and meaningful if the source is used to make claims that are either false, or outdated. Based on what I read up on the issue, the Catholic Encyclopedia did not say anything that is historically in dispute, as outlined above. If you have evidence to the contrary, please provide references.
Again, the issue was an often made claim that Maronite Christians were in an "unbroken" communion with Rome "from the beginning." This is the claim made by the Maronite Church. Most historians disagree. So does the Roman Catholic Church, based on its own documents.
RE: The Maronites and the Antiochian tradition
The period after Chalcedon was a time of challenge and sadness for Antioch. In the West the Goths laid waste to Rome and Western lands. In the Middle East, the Patriarchs of Antioch embraced Monophysitism and were referred to as Jacobite. Antioch had formally rejected Chalcedon. A tiny Greek community remained. In time, those that accepted Chalcedon and their leaders were driven out of Syria and into the mountains of Lebanon. This community became known as the Maronite Church.
The Byzantine emperors made Rome a vassal, initiating the Byzantine Captivity of the Papacy. Political power was much more fragile in the Middle East, however. The Persians having driven a wedge between Constantinople and Jerusalem, finally overtook the entire Middle East in the early 6th century. Shortly thereafter, the Muslims conquered the entire region. The Muslim leaders successfully repressed any remaining Chalcedonian Christians, who at the time were seen as allies of Constantinople. The only Chalcedonians that remained of the Antiochian tradition were the Maronites, who lived in geographic isolation.
During the Roman reunion councils, East-Antiochian and West-Antiochian traditions affirmed Chalcedonian faith and Roman communion, among whom were the Maronites. Because the Maronites were under the Antiochian Jacobite and Nestorian (those of the East-Antiochian tradition) cloud, they were made to profess the Chalcedonian faith. There is no internal evidence that the Maronites had ever rejected Chalcedon or Roman communion during their centuries of Lebanese isolation prior to reunion. Rather, because they had descended from a tradition that became overwhelmingly non-Chalcedonian, to remove any doubt, they professed the faith of the Church.