Hi Terry - you have taught me a new word, MacGuffin.
I am familiar with the WT history and this word in particular, I have not met many witnesses that can explain it and few can explain it as clearly as you have. So thank you. This concept that they've messed with is what caused me to realise something was BADLY wrong.
When I had to do a stand-in talk on the subject, the Theocratic Min School instructor couldn't understand the word and he couldn't understand why my conscience wouldn't allow me to give the talk. Over the years I have tried to explain to various ones why their use of parousia is a MacGuffin :) but I get called a scholar. And that is meant as great insult, not a compliment.
On the otherhand if I am explaining the MacGuffin to an elder who actually does know a bit of Greek, they go nuts at me or try desperately to change the subject. So my point is, I never found them keen to mention Greek words, especially in my presence/parousia.
So I carried on learning Greek and carried on learning Hebrew and I found the Greek Interlinear very useful.