I dont see being the lighthouse meaning sitting around waiting forever. Yes,it may involve holding off on a new relationship but one that most aren't ready for anyway. To me, being that lighthouse, static or not, is just about continuing to move forward with your life and changing into the best person you can possibly be(which we should all be doing anyway).
That better person may be a beacon that shows the WAS the way home,it may not. The work to change themselves is still on them to figure out, that beacon can just have a small amount of influence to point them in the right direction.
After someone is divorced and is ready for a healthy relationship, then is the point they decide if they close to door to R with the WAS or keep standing. Each person is going to have a different time line of when that happens. I think many use the letting go line as a way to jump into a new relationship when they know they aren't in a healthy enough place to do so. It's more a means to force the pain away than actually moving on.
Point being, you can be the lighthouse and move forward with your life at the same time. It doesn't have to be a separate action when you let go.
Accept what is, let go of what was, and have faith in what will be
