I have taught that the definite articles in John 14:6, "...the way, the truth and the life..." constituted "one of a kind" or "unique" articles. However, John 14:6 is not as an example of this use in your grammar. What kind of articles are they?
Since there are almost 20,000 articles in the NT, you can understand why I don't include all examples, or even all major examples of such. Whether the articles in John 14.6 are monadic ("one of a kind" or "unique") or par excellence is difficult to say. If monadic, the implied context of "the only way to God," etc. would be part of the universe of discourse. If par excellence, the implied context would be "the way that really gets you there." One difficulty with the monadic view is that Jesus is not the only truth--unless one is seeing the truth in personal ways that relate to humanity, but it gets quite convoluted doing that. The same for the life. The whole is very much like 1 Cor 8.5-6: Paul says that there are many gods, yet "for us there is only one." Many have the title, but only one really deserves the name.
The bottom line is that John 14.6, any way you slice it, strongly affirms the uniqueness of Jesus as the only one through whom one can gain access to heaven, God, and eternal life. This, in fact, is explicitly stated by Jesus in 14.6b. Of course, then there is the issue of whether one needed to be cognizant of Jesus to do this--an issue that we need to address with sufficient nuancing because of the situation of OT saints (how could they know anything about Jesus personally??).
My suggestion would thus be: Don't focus on the grammar so much as the overall thrust of what the Lord was saying. He is the only way to God. The English text is clear enough on that point. Then, develop the whole argument about personal knowledge once the crucifixion was a historical event.