I would like to think the child is missing the bonding and fun the two of you enjoyed with the robot guy. The child may be missing the experience of being with you and the robot guy. I would look for more activities you can explore with the child.
That sounds dangerous to me. Not like I think you did something wrong or exposed your daughter to danger at all; it was probably a really useful exercise. The scary part to me is how readily she accepted it as human, or friendly.
We already know how well people are deceived by text and images. Imagine if they're getting phone or video calls from "people" who keep them company for hours at a time. Imagine if they're accustomed to it from an early age. The notion of dealing with a real, messy, rough on the edges, honest human being well become an intractable frustration.
I can see how it's worrying, but mostly as a replacement for real connections - if instead it supplements them, then not so bad.
Most children love talking to a fun adult who enjoys talking to them. As parents we hope to be that adult for them most of the time, but of course that's not easy to do all the time.
If parents made a tool like this a crutch and it replaced quality time with them or they were less likely to hang out with their friends, then yeah that's a big problem. If they use it as a learning aide or occasional fun diversion, it seems great.
Tangential, but... when my daughter was 8 or 9, we read _I, Robot_ together, and both both cried when Gloria's parents decided to separate her from Robbie, her robot companion. Such a fond memory to this day.
Today, she asked "where has that robot guy gone?". Crying now because I won't let her talk to Miles anymore.
She has already developed an emotional connection to it. Worrying indeed.