Did the church suppress the true gospel in their selection of the canon?

I have been searching for a conclusive answer to this question for some time. I read this last week and has been by far the best answer, burying the question for me.

The Syriac Bible was a conservative text, to a degree that demands our attention. In recent years, accounts of the early church claim that scriptures and gospels were very numerous, until the mainstream Christian church suppressed most of them in the fourth century. This alleged purge followed the Christian conversion of the emperor Constantine, at a time when the church supposedly wanted to ally with the empire in the interests of promoting order, orthodoxy, and ecclesiastical authority. According to modern legend, the suppressed works included many heterodox accounts of Jesus, which were suspect because of their mystical or even feminist leanings. 

The problem with all this is that the Eastern churches had a long familiarity with the rival scriptures, but rejected them because they knew they were late and tendentious. Even as early as the second century, the Diatessaron assumes four, and only four, authentic Gospels. Throughout the Middle Ages, neither Nestorians nor Jacobites were under any coercion from the Roman/Byzantine Empire or church, and had they wished, they could have included in the canon any alternative Gospels or scriptures they wanted to. But instead of adding to the canon, they chose to prune. The Syriac Bible omits several books that are included in the West (2 Peter, 2 and 3 John, Jude, and the book of Revelation). Scholars like Isho'dad wanted to carry the purge further, and did not feel that any of the Catholic Epistles could seriously claim apostolic authoriship. The only extraneous text that a few authorities wished to include was the Diatessaron itself. The deep conservatism of these churches, so far removed from papal or imperial control, makes nonsense of claims that the church bureacracy allied with empire to suppress unpleasant truths about Christian origins.  -Philip Jenkins The Lost History of Christianity, Harper Collins 2008. page 88

I would highly recommend Jenkins' new book. I'm just in the middle of it right now. Might post more from it later.