Yes, you can change the variable - unless you have set custom names before and are using these in PHP filters.
What SoSci Survey will do is this: It will register an alias for the respective variable, and use that alias in the downloaded data set.
For PHP code that means: A value('AB01_01')
will still find the variable A01_01 (technical name), but value('FamilyName')
will also work if that is the variable's new name.