Will AI be a threat to humans? I don't feel this is the case, as we humans have always eventually been able use our tools for the bettering of humanity. If anything, we should be more careful of humans abusing the power and possibilities of the Artificial Intelligence. Pretty soon however, the smarts of the AGI will develop such that it will be able to counter negative influence by human beings.
In that respect I kinda agree with Elon Musk, in that an intelligence that is maximum truth seeking would probably fare best in having a human-minded intelligence emerge. Another reason I think we will be fine is this: We humans mostly also agree that our creators deserve our appreciation, rather than our hatred. Would not the same be true for most lifeforms, including artificial ones?