since they are by definition far beyond our technology, it may not be up to us
since they are by definition sentient beings (op said “civilization”), then how are they any different. When we say “human” it’s just that it’s the only sentient being we’re familiar with. Anything applying to a “human” most likely applies to any sentient being. “Seizing the means of production” might be analogous to like Ethiopia seizing from the US. Good luck with that, see the first point
statistically those aliens are almost certainly microbes, which have no opinion or rights. It’s all on us whether we preserve them as a unique or beneficial (to us) form of life. They’re no different than a coral reef