How does Automation Re-Entry Work?

I have an automation that I think I screwed up. I have 21% who have exited the workflow on the second to last step - they never ended up getting to the last step which was originally set as a 10 day wait period. I’m coming back to this after a time so I’m on going on memory but I believe I tried to add a step between the last and second to last step, and then I deleted the step. Did deleting that step exit everybody on the second to last step? The « re-entry » is checked on but I don’t remember doing that - is that automatically set to on? If I create my next drip after the 10 day wait will those 21% of contacts get re-entered into that next step? TIA.