The children were not assigned the above names at birth. A few weeks ago these new names were presented for Maxwell, Augustin, and Samantha Grace. I believe it was A. J. (Max) who came up with them, and I believe they stem from a popular children's TV show.
I doubt A. J. and Michael will stick with their new names for long, but Goldie might just continue to be a Goldie for good. Boo Boo (Turner) has been Boo Boo (or sometimes "Turner Boo") for some time now, although he may shake it off in grade school.
I gave "Burbank" his name myself. Since Turner and Truman both have "T" names, I was always calling Turner "Truman" and Truman "Turner". In honor of Jim Carrey's movie, Truman became "Burbank".
A note of irony is that Gus's initials are actually "A. J.", so why is Maxwell A. J.? Oh, well, whatever works...