[dmm]

Once discovered, natives might advance much more quickly than they would otherwise progress if left undisturbed. That is a dominant theme in many sci-fi sagas. For instance, how many StarTrek episodes mention the "prime directive?"

Remember, in SEIV there are supposed to be scads of independent traders roaming the galaxy. The unscrupulous ones would be willing to trade technology for a green Orion slave girl.

Plus, empires would have their own reasons for "helping" the "natives." I think a good example would be native populations on Earth who encountered European empires. It didn't take the Plains Indians (e.g., Lakota Sioux) very long to incorporate metal knives, horses, and rifles into their culture.