My Paternal Grandmother joined IBSA as a young married woman about 1903. Her oldest daughter (my Aunt) was baptized in 1926 as a Bible Student after Rutherfraud took over. My grandmother and aunt stayed with the original group and had the heavenly hope. My father and his brother were baptized in1936 after they took the name Jehovah's Witnesses and had the earthly hope. Nobody thought it was weird. LOL In fact, my Aunt married an "other sheep" man.
Before Grandma died in 1950, Knoor was Pres. She was a true believer and went along with the changes in her lifetime. My Aunt died in 2004 ONE DAY after turning 100 years old! She too was able to adjust to the many changes without any noticeable disagreement.
My guess is that they would go along to get along. As has already been said, when the changes are gradual they are often accepted.
OTOH, my father who died in 1969 was the kind of zealot who had a quick trigger + hot temper. If he were alive today he would be 112 YO. But if had lived to know of The UN scandal, Gays at Bethel, CA cover-ups, and Blood Fractions to name a few, he would be Outspokenly Out!
Not everyone is the same - even in the same family.I believe the crazy unrecognizable religion JWs has become lately though, especially with the Idolatry of the GB, would distress ALL of those old-timers.