One of my ancestral families "switched" churches. I knew a rough time period of when it happened, but did not have any way to narrow the time frame until I viewed the children's christening entries. The church where they were baptized helped me to pin down when they switched.
Interestingly enough, the "switch" was within a year or two after "Grandpa" died. Grandpa was a member of the church they left. It has left me wondering if the family waited until his death to leave the church. There's no "proof," but the time line makes me wonder.
Did your family wait until someone died to move, change jobs, change churches, etc.? I have one family where I'm pretty certain they waited until "grandma" died to get divorced--or at least it really looks that way.