It's hard to overstate how important the "vindication" doctrine was to JWs at one time.
I was only 11yo at the time the the vindication teaching was dropped so i dont remember it being a big deal to me. But now that you mention it i remember as a family studying the Watchtower on Saturday evening and my dad getting exasperated at us kids not getting the point "WHY did Jesus come to earth?", we were making wild guesses trying to get the right answer and my sister suddenly shouted "to VINDICATE Jehovah's name!" and my dad said "Yes! Finally! haha".
So it seems my dad still clung to the vindication angle. At least at that time.