Campaigns queue up all actions against the contact at the time the contact joins the campaign. What is in place when they are added to the campaign is the way it will play out. If you make changes, they will only affect new contacts being added to the campaign after the changes.
To answer the original question:
[quote=17750:@chizuoka@gmail.com]
Would a contact who has NOT trigger the 10 day wait rule still send email X in 10 days, or will it change to rules after the change?[/quote]
The contact in this case has already triggered the 10 day wait and so it will not change.