The data structure mentioned in Virtual Spacetime: Model, Technology, and Applications of Spacetime without Physical Constraints is referring to this one. - It’s Nice to Know the Names Already Attached to Concepts
According to https://en.wikipedia.org/wiki/Retroactive_data_structure:
In computer science, a retroactive data structure is a data structure that allows efficient modifications to a sequence of operations that have already been performed on the structure. These modifications can include retroactive insertion, deletion, or updating of an operation that was performed at some point in the past. 1