After the initial colonization of Londinium and Sihnon, Bernadette was the first planet to be terraformed and settled by humanity. It is a traditional launching point for those leaving to settle on other worlds. Settlers arrive here from other planets in the core and make preparations to set off for a new life on the Rim (The settlers in Bushwhacked left from here on their way to New Hall.)
Non-canon: The moon is named for Alliance war hero Bernadette Sheridan-Hale (see the Unification War).
(Just for the record, in making up non-canon names of generals for the Alliance in the Unification War, I came up with Bernadette Sheridan-Hale myself, because it seemed like a good name. It was only afterwards, when working out the (non-canonical) background for this colonial staging-ground, that I realized what a great connection the two made.}