Hi Craig,
I have searched many documents and done some tests on this requirement, and found that it is not available to remove email address from Email Options section of a distribution group(DG) currently.
When you change the email address of the DG, the previous emails address of the DG will be added in the Email Options section. So that when the owner change the email address of the DG, all the emails sent to the DG will not been lost. This can protect the mail flow.
Thanks,
Linda Wang