I have to say, I think that is crazy.
There is a differernce between saying something is a bad idea now, or unnecessary, that its a sensible law that protects young women in the 21st century UK, and that it is a fundamental violation of human rights. Because if it is a fundamental violation, then it really is across all time and place.
My grandmother was married at 17. She had finished school and was working and supporting herself as was quite common in those days. Was it really so strange that she might decide to get married?
Similarly, 500 years ago, or 1000 years ago, would it really be bizarre for a young woman of 16, able to run her own household, doing the exact same work as her parents on the farm or in some kind of trade, to wait to marry?
Alexander the Great set out to conquer the world at 17, who was going to tell him he couldn't get married?
I think some of these things undermine the idea of fundamental human rights, tbh. Things can be a good idea, even a necessary idea for the times and circumstances, without it being a human rights issue as such.