Sorry, what I intended to say was there are halachot and eitzot there about negative information between the two parties and others. But, I don’t think the c”c specificly states broken engagments although that is usually the purpose of those that wish to harm because they are nogeah bidavar.
The explanation I wrote is just from general halachot in the c”c.
But, again, this does not nesecarily apply when a side is full of talmedei chachamim and yirei elokim because they will harbor no resentment. You need to know before asking them for information if there are any unsettled feelings. Personally, from a family member, we were asked about a person who broke off an engagment. B”H, we had no resentment. The girl was really good but not ready at that point; she was pushed into it. We were able to give good, reliable information and we have received the invitation in the mail. For some this applies and for others it does not.
Many times the c”c says you need to know the tevah of others.