Your assumptions are the following:
1. People don’t change over time.
2. If they do want to change, they must plan it in advance and ask your permission first, and if you don’t approve, they can’t change.
3. If it is a religious change, and it’s to become frummer, and it won’t affect the marriage [impossible], then you have no say.
—-3a. But if it does affect the marriage, the other can reject the increase in frumness.
4. If it is a religious change, and it’s to become less frum, it’s always a [deliberate] betrayal of Hashem and their spouse.
#1 is unrealistic,
#2 is incredibly controlling and intolerant,
#3 is untrue,
and
#4 is dangerous.