I have found that laterly other family members in the same list get their names changed too - but just to be on the safe side I change the father and put a note in the comments box "joe blogs, his wife and 9 children"
This seems to work - although I agree it didn't used to be the case and one had to do them all one at a time.
When you find a person with an amended name - one with a blue blob +. not the yellow triangle - click on that amended name and up comes the details.
Not everyone is contactable, it seems, but I have made and received several excellent contacts through this amendement posting on ancestry.