Does major renovation = selective demolition?

The RSD review for the majority of the mid-century modern schools is "complete replacement." While they have not yet equated "complete replacement" with "demolition," we can assume these buildings are threatened. I initially thought that Mahalia Jackson Elementary might be the only mid-century public school to survive the initial RSD review. Then I found this.

While the RSD review said "major renovation" this document suggests they are planning a "demolition." This is the main page for information about the so-called "selective demolition" of Mahalia Jackson Elementary. Can the RSD please define "selective demolition?" And how about the difference between "complete replacement" and "demolition?"