I don't share your view that it will be at all clear to people that these things don't matter and have no rights. We have a very powerful (sometimes for good, sometimes for ill) ability to empathize with things that we see as similar to us. As a case in point, we're currently in the midst of a major societal debate about the rights of unborn children that exhibit no signs of sentience (yet).

What happens when people start building real emotional bonds with these fake intelligences? Or using them to embody their dead spouses/children? I think there's going to be a very strong push by people to grant rights to these advanced models, on the basis of the connection they feel with them. I can't even say definitively that I will be immune to that temptation myself.