I received a comment that more or less, that foster adoptees are different because they are still connected to their birth families and child keep their “original names”.

This is not the truth for the majority of foster care adoptees. People seem to be surprised that foster adoption is no different than any other adoption.
Foster adoptees do have more obstacles to overcome due to the trauma of abuse and neglect. A lot of foster adoptees are faced with a childhood filled with therapies to help them learn to deal with the anger and rage they feel from the trauma.
Some are haunted by the memories of sexual abuse, being beaten day in and day out, burned, locked in closets, the permanent physical damage, etc., that they struggle with behavior problems and attachment issues. Some continue the struggle through their early adulthood and a few spend their lives struggling. Many do have normal lives and manage to work through the trauma.
It is very common that a lot foster care adoptees do not have ongoing contact with their birth families after adoption. These parents are not placing these children up for adoption, because they cannot or choose not to care for them. These parents lose their children due to their abusing or neglecting their own children.
Some foster children that are older when placed into foster care do still maintain contact with their birth families or siblings but not all do. In most cases, they see their birth families a couple of times a year so. Their birth families are no more involved than a birth family in an open adoption.
Child Protective Services in some areas and some cases will try to work out contact for the birth parents that the adoptive parents feel comfortable with instead of a lengthy court case if they are willing to relinquish their parental rights.
More reading:
Foster Care Adoptees: Reality
Not all Biological Parents Deserve Additional Help
How Many Second Chances?
Open adoption in foster adoption