There are two things to clear up. And then, based on that clarification, make a comment.
First, until the founding figure of doubting scripture wrote about 1750, most likely everyone believed the historical idea that the New Testament was written between 45 and 105 CE. This change in attitude toward the traditional dating postdates the Reformation that took place from 1517 to 1648.
So, there’s virtually no doubt that the Reformers agreed with the historical teaching that the New Testament was penned between the times of the first and last apostles to die (James and John sons of thunder).
Second, no one would seriously dispute that the apostles spoke first and then wrote. Irenaeus circa 180 CE for example says this (first quote below). Scripture itself says it here and here among many other places!
The real dispute in Irenaeus’ time that over centuries would nonetheless develop and later lead to the Reformation was the conflicting idea that the apostles spoke orally something that was necessary to one’s salvation, but failed to write it down. In other words, everyone agreed the apostles spoke and then wrote. The dividing dispute was whether what they spoke had a bearing on truth found not only in scripture (necessitating a teaching mechanism), but also apart from scripture (requiring another source of truth). Irenaeus puts it this way;
- When, however, they [the heretics] are confuted from the Scriptures, they turn round and accuse these same Scriptures, as if they were not correct, nor of authority, and [assert] that they are ambiguous, and that the truth cannot be extracted from them by those who are ignorant of tradition. For [they allege] that the truth was not delivered by means of written documents, but vivâ voce: wherefore also Paul declared, “But we speak wisdom among those that are perfect, but not the wisdom of this world.” And this wisdom each one of them alleges to be the fiction of his own inventing, forsooth; so that, according to their idea, the truth properly resides at one time in Valentinus, at another in Marcion, at another in Cerinthus, then afterwards in Basilides, or has even been indifferently in any other opponent, who could speak nothing pertaining to salvation. For every one of these men, being altogether of a perverse disposition, depraving the system of truth, is not ashamed to preach himself.
AH Book III Chapter II P1
For Irenaeus, the “system of truth” is found in nothing other than preaching scripture.
Finally, many misunderstand Irenaeus’ support of tradition, as if, again, that tradition was not already known via scripture and faithful men. Irenaeus is very keen on the idea of faithful men handing down faithfully (identically) that which scripture tells, that which apostles knowingly said. That same tradition could once be found identically in the church, whether at Rome, Smyrna, Ephesus, or elsewhere. Again, here is Irenaeus;
- But, again, when we refer them to that tradition which originates from the apostles, [and] which is preserved by means of the succession of presbyters in the Churches, they object to tradition, saying that they themselves are wiser not merely than the presbyters, but even than the apostles, because they have discovered the unadulterated truth.
AH, Book III, Chapter II, P2
Tradition must originate from apostles (written scripture) and is maintained, not changed, added to, or subtracted from, by means of a succession of faithful elders in the churches. Those who object to this system do so on the basis, again, that the apostles left something out of their writings that others discover.
So, the Reformers would have agreed with the historical view that the apostles spoke first from 30 CE to about 105 CE and then wrote from about 45 CE to about 105 CE.
Further, the Reformers would be agreeing with the historical view that the apostles did not leave out anything necessary for one’s salvation from their writings that we all call the New Testament.