As Josh said, the wait step will still run—it's just that sometimes that in and of itself can be the problem if you decide you want to revamp your scoring, need the record to not run for whatever reason due to changes made in processes, etc. I'm very wary of running a wait step for more than a few days as a result and have gotten into the practice of setting up an "emergency override" field of sorts to check against and remove from flow as a manual brake in the event you don't want records to perform the flow set up after the wait step.
The main issue with wait steps is that once someone is in it, they remain in it even if the campaign is deactivated and then proceed through the rest of the flow steps.
What I've implemented in the past are the following criteria for my lead decay program
Run on a schedule (weekly, daily, etc)
- If not clicked on email in last ## days
- If not filled out form in last ## days
- If not visited webpage in last ## days
My decay rate in the flow steps took into account where they stood in my scoring model.
The higher up they were, the faster I wanted them to decay so that they came down at to a level where they were showing no or little engagement at the same rate they could scale up in the scoring.