There’s some great insight here that I agree with!
One other aspect to consider, adopting from foster care may mean that family can have contact with the child. Not necessarily the parents (possibly tho), but sometimes a grandparent or aunt cannot raise the child, but really wants to be involved and a judge will allow that.
If the adoption is fully closed, no contact with anyone, and the infant happens to not be from a local family, you could rename him or her without issue.
Ultimately, you are the adoptive parent, but if there is some family contact or the family is local, a full rename may get the relations off on a bad foot.
Also, you won’t know any of this information for a very long time, most likely. If you’re adopting from foster care, the child will already be in your home. You’ll be used to calling him/her by their birth name, and so will your entire family. Generally, when people change a child’s name, it’s as soon as they receive the baby (not usually thru foster care) or the process takes time with the child’s involved in the decision (so at least 5 or 6 years old).
Infants removed from their parents care and immediately placed in a foster-to-adopt home is also pretty rare. Judges want to give the family every opportunity to allow someone blood related to care for the child. The mom would have to be a frequent flyer of having babies and getting them removed, in which case, they also want to try to keep the siblings together as much as possible anyway.
This is just my experience from working within the foster care realm for… idk, I guess 4 years total… something like that