My father's cousin, auntie told me when a bride is fetched from her home to her hubby home, everyone will hide or out of the house. It is heard that a bride has strong aura. Strong aura can easily offended anyone in the house.
In order that mother in law and daughter in law have a peaceful life of living together, it is best mother in law avoid meeting the new bride when entering the house.
It is just a tradition I heard today. True or not true, it is you to prove.