It's glorified to-do lists with an opinionated cadence on how often features get deployed. Do we really need an entire discipline to communicate those simple things.
How flexible are we with requirements ? How many stages are in the to-do list ? How many hierarchies are in the todo list? How often do we features to be deployed ? What more do you need to know ?
Takes 1 long meeting establish a well-communicated bespoke development cycle for each team. Do we really need a phrase for that ? My experience tells me that the system gets sub-optimally molded to suit the implicit development style of the team whether you like it or not.