They might (or might not). Extraterrestrial beings might also need moral standing. It is ok to spend a bit of thought on that possibility. But it is a bad argument for spending a non-trivial amount of resources that could be used to reduce human or animal suffering. We are not even good at ensuring the rights of people in each country, and frankly downright horrible for denying other humans from across some "border" similar rights.

The current levels of exploitation of humans and animal are however very profitable (to some/many). It is very useful for those that profit from the status quo, that people are instead discussing, worrying and advocating for the rights of a hypothetical future being. Instead of doing something about the injustices that are here today.