Delian said:
I dunno. I feel like growth is a bit more specific and it should be used if it fits. Growth is used primarily for living things, so if the thing is organic, if it grew in the past, then growth should be used.

For instance: Trees grow. They don't expand.

Any other native english speaker that believes there's nothing wrong with expansion in all cases?

Growth is over long periods of time, expansion is over short periods.