Yes, there was a Plaza in Boyes Springs. The first half of the Plaza Center Building was built in 1951. It spared the palm tree. The second half, the part that houses the post office, was built in 1956, and spelled the end for the beloved tree.
The pre-1956 Zan photo below shows the tree peeking over the top of the building. Notice the “Resort Club” sign in the background on the left.
Photo courtesy of Bruce Griewe. Taken in 1942.