Rev,
The means are measured by the outcome. If it doesn't produce, it must not to be working. Do we see a coherent and unified understanding of the Abrahamic God's message to humans? The Muslims, Jews and Christians all pretty much went seperate ways. Or let's reduce it just to Jews and Christians. Do they agree on what the Hebrew scriptures say and mean? No that's a complete mess. No wait, let's reduce it to the Christians. Are Christians all of the the same mind? No? Ok let's just bring it down to the not-Catholics who came hundreds of years afterward. Surely God is so clear that they are unified due to God's clear information sharing. No again? Wow. There are huge gaps between different schools of thought all streaming from the same Abrahamic God. That God is really terrible at providing accurate clear information at critical intervals isn't He? No one can agree on what the hell He has said or what the words mean. But hey, if they don't agree, we can just explain it by calling those people evil and not God's people right? That absolves God's failed communication plan doesn't it. Right (sarcasm).
Furthermore. They probably did not say "new light" because they didn't speak English. That's a semantical argument you're putting forth. The question is whether the concept was present. Yes it was. Let's just look at the scriptures and reason on it:
1. And after journeying through Amphipolis and Apollonia, they came to Thessalonica, where there was a synagogue of the Jews. 2. And as was the custom with Paul, he went in to them and for three Sabbaths reasoned with them from the Scriptures, 3. Expounding and demonstrating that it was necessary for Christ to suffer and to rise from the dead, and testifying, "This Jesus, Whom I am proclaiming to you, is the Christ." 4. Now some of them were convinced, and joined themselves to Paul and Silas, including a great multitude of devout Greeks, and of the chief women not a few. (Acts 14:1, 17:1-4) (dunno translation, I ripped it off the internet).
If it walks like a duck. Quacks like a duck. Then it's a duck. That above there is new understanding. He completely changed the game and then called anyone who did not believe in the changed game a person who was wrong, No longer part of God's people. YET if they were born before Jesus, say I dunno, 15AD, and were doing their Jew thing in Thessalonica, they WERE of God people, doing the things the Jews did. But now, in say (I don't know, just gotta guess) somewhere between 45CE and 55CE, they are not. Why? Because the game changed on them and they did not change with it. According to Paul of course.
That's crazy isn't it. They are a man of Gods people for years then all of a sudden ... they aren't. Just sitting there doing the same thing. Why not? Because they did not do what? Accept a totally HUGE new understanding of the Hebrew scriptures. That makes JW changes seem almost cosmetic.