And that's really what this is about: what is reasonable? If a group doesn't want to learn about past acts of violence and prohibits anyone else from studying it, is that reasonable? Are the victims of said violence also not entitled to this research?
Italian Churches may close their doors, as is their right, but Italian churches aren't preventing entire areas of research from happening. Churches did in the past, and still try today at times, and people generally aren't too positive about that. Even most hard-core young-earth creationists don't really make any effort to stop research from happening: instead they do their own "research" in an attempt to refute the genuine research.
I would say that a large part of why Western culture has slowly becoming more liberal and empathic over the centuries is the study of history, and understanding what happened, and more importantly why.
I would strongly encourage everyone to object to anything they don't like, either as an individual or as a group, but I think it's foolish to simply shrug and accept any objection without any examination on how reasonable it is. "I don't want you to take a picture of me" is reasonable. "I don't want you to take a picture of anyone of my ethnic group" is not.