@CBW 

I am not 100% sure but I think it will remove people from the segment because the condition is… IS IN list.. not WAS IN list but I’m not sure so maybe someone from klaviyo support can confirm or deny this..

Hello @CBW,

@Bobi N. is spot on! It would all depend on how you have your segment created. If your segment is based on a list using the definition of “If someone is or is not in a list, Person is in X list” then deleting the list would remove all users from the list. 

However, deleting the list of contacts would not delete the profiles themselves as deleting the list would simply be deleting the grouping of contacts; not the actual profiles. If you were curious about how Klaviyo treats contacts and profiles and how to fully delete a list of profiles or contacts, you can find out from the Understanding Who Is in Your Account and How to Delete, Merge, and Export a Profile Help Center articles.

I hope this helps!

David