System Development Life Cycle (SDLC) isn't methodology. It is...life cycle :-)
Each system (product) goes through several phases during it life. This always happens and is not dependent on methodology.
These phases could be mixed in different ways (Waterfall vs Iterative and Incremental approach). But all of them are present.
Some methodology may or may not describe how to do some of these phases. For example: Scrum doesn't describe how to do the initial phase, and says little about integration and testing. Almost nothing is prescribed in Kandan. But it doesn't mean, that there are not any of these phases in the concrete implementation of Scrum or Kanban. It means that in concrete processes these phases may be implemented in any way you wish.
In some development processes, phases may degenerate, such that you may think that there are no such phases at all. For example, let's imagine some software development process where there were no planning meetings, no planning documentation and so on. You might think that this process had no planning. But planning is present in this process. When a developer starts to implement requirements, he can't do all of them at one time, so he will plan what he will do first, then he will do second etc.
So, the answer is:
- Methodology may not prescribe what activities should happen during SDLC phases.
- But product (system) will go through all SDLC phases anyway.
