Substitute "hosts" for "bride's family", which is what the person/persons paying for the majority of the event. Is there ANY other situation or event where people wouldwould demand of expect that relatives of the non-hosting, involved person would be considered entitled to, hold on... proclaim, "It will be a cold day in hell before someone other than my child tells me who I can and cannot invite to my child's wedding. I'd love to see my future DIL's mother try it.
"?
It sounds like a threat, to me.