With the proliferation of cloud solutions, I feel there is a new step in the traditional current state, future state, gap approach.
There will always be the need to have a solid understanding of the current state. The current state is the starting point for the change so it is required not only for requirements but also for the plan going forward.
Without understanding the current state you risk not understanding all the requirements.
After the current state, when you are moving to a cloud solution, you need an understanding of the paradigm of the solution. What does the solution provide and how does the solution provide it. This understanding is required before you start defining the future state. The future paradigm forms the constraints for the future state solution.
Oftentimes, the future paradigm requires businesses to change the way they do things. The closer the business is to the future state paradigm the easier the transition to the future state.