Hello Techie,
When GroupId expires a group it makes two changes
1-Changes display name and adds Expired_ prefix to it
2- Make changes in Extension Data stamping it to be expired. Extension Data is used by GroupID to keep its information about groups
In the reference of Active directory there is no change except the display name of the group.
After a group is expired we can view the group by clicking My Expired Groups, from where we can renew or delete the group.
I hope this answers the question.
Daanish