Animals in labs are treated abhorently the world over, it's not an exclusively Chinese thing.
I don't know what the wider aim of the experiment was. If it's used as evidence that nope you can't transplant a uterus into a man and expect a healthy pregnancy to result then great. It's interesting that it's clearly not just the uterus and hormones, there must be something else about the female body that allows gestation. It would be interesting to learn more, especially if it is looked at in the context of understanding female fertility with the view to improving fertility treatments. There's still loads we don't know about the female reproductive system.
Of course the ethics of using animals like this are dubious but, as I said, experimentation on animals happens everywhere, not just China. Maybe they treat the animals better in the UK...but whether they do or not there's no getting away from it that UK lab rats live short and unpleasant lives. When I was at university one of my peers final year dissertations involved grafting tumours onto rats..