Why is human history so important, or useful, in predicting aliens? Why would it be better than:
Human history's importance gets diluted once advanced aliens are encountered - though the chances of any such encounter soon seem slender - for various reasons. Primitive aliens would still be very interesting.
Experiments that create living humans are mostly "fine by me".
They'll (probably) preserve a whole chunk of our ecosystem - for the reasons you mention, though only analysing non-human life (or post human life) skips out some of the most interesting bits of their own origin story, which they (like us) are likely to be particularly interested in.
After a while, aliens are likely to be our descendants' biggest threat. They probably won't throw away vital clues relating to the issue casually.
As Luke mentioned, I am in the process of writing "Responses to Catastrophic AGI Risk": A journal-bound summary of the AI risk problem, and a taxonomy of the societal proposals (e.g. denial of the risk, no action, legal and economic controls, differential technological development) and AI design proposals (e.g. AI confinement, chaining, Oracle AI, FAI) that have been made.
One of the categories is "They Will Need Us" - claims that AI is no big risk, because AI will always have a need of something that humans have, and that they will therefore preserve us. Currently this section is pretty empty:
But I'm certain that I've heard this claim made more often than in just those two sources. Does anyone remember having seen such arguments somewhere else? While "academically reputable" sources (papers, books) are preferred, blog posts and websites are fine as well.
Note that this claim is distinct from the claim that (due to general economic theory) it's more beneficial for the AIs to trade with us than to destroy us. We already have enough citations for that argument, what we're looking for are arguments saying that destroying humans would mean losing something essentially irreplaceable.