wozza
... and really with all the changes in recent years ,this question should be asked bt JWs today to test their belief system which is based on a group of men which changes all the time over the years and so does their teachings.
For a still in JW the teachings never changed.
They hate the word "change" in this context.
JW Answer: ALL core teachings are still the same. And for some small things - there was brighter light (NOT NEW light) . The light always geht brighter and brighter and this is consistent with the bible.
You can't argue with a (still in) witness - that's my experience with my parents.