AFAIK, when a new term is imported, it will get an arbitrary ID, similar to posts. If all you need is a term attached to some posts, then it’s fine, because WordPress handles that automatically.
However, if you use the term ID somewhere else, like in the Customizer, you can’t get the new term ID.
I’d suggest you should not rely on the term ID. Why not using term slug? It’s not kind of 100% unique, but in most cases, it remains the same when you import. And you can easily get the term via get_term_by.