Scott
Scott, the detached section across Bear St. (now connected by a bridge; originally you had to cross the street no matter what the weather) is or was originally called Crystal Court. Used to have major dept stores as anchors. Opened in the mid to late 1980s. I believe there was a Robinson's store in it when it opened, but eventually May and Robinson's merged, sort of eliminating the need for two stores in one mall. The former Robinsons in Crystal Court is now Macys Home Furnishings.
I believe the other anchor in Crystal Court's south end was Broadway, but now it's Crate and Barrel. Now, as you mentioned, it's a haven for large stores like Crate and Barrel that need loads of floor room. The tenant mix sort of occillated over the years. I think Segerstrom tried to make it ultra high end at first. I remember that one of only two Kosta Boda galleries in the USA (the other in NYC) was originally in Crystal Court, then it moved to the main section of SCP, and it closed within the last couple of years. Now the mix is more middle of the road: Crate and Barrel, the retailers you mentioned, etc. They seem to finally have hit a happy medium and the formular evidently works.
I grew up in San Diego and didn't move to OC until 1982. So I never shopped there until 1982. However, I do remember pulling off the 405 on a family trip, coming home from LA, to check out the new addition to the Plaza in c. 1977, with the Nordstrom store and all the new retailers added when the Nordstrom wing went up (in a later late 80s expansion, a larger Nordstrom store was built, and the old Nordstrom store is now occupied by Macys). The current Bloomingdales store was the original May Co store that opened the plaza in the 1960s. The carousel was added in the first expansion with Nordstrom in the 1970s.