Learning Plan update for renewal

Summary

Changing out courses in a learning plan and it's effects

Content

So I am sure this is on here somewhere but I didn't see it. We have a learning plan for drivers about hazmat safety that renews every 2 years. They realized that they need to replace 2 of the courses with new ones, for those users that are already complete with the learning plan, will the learning plan remain complete until their scheduled renewal date, or will it turn everyone who had been complete to incomplete? We have 4000 some drivers that would be affected so wanted to make sure. 

So basically 4 current courses in the learning plan, 2 would be removed and 2 new added. What would this do to completed drivers?