Question on adding a “personal email”as a recovery option..Please help

If I add a recovery gmail to my primary ID,  it says the “changes will be reflected across all Xfinity accounts”.  

I can access this primary email now because My cell number is listed as recovery option. But I would also like to add a new gmail account to have a second recovery option on this primary.

Can anyone from Xfinity tell me what that means?  

I am locked out of 3 secondary emails now for a week tomorrow.  I am calling CSA in the morning

The ones I am locked out of did not have a recovery option to change password and I cannot do it from my primary which I can still access.  I will have to add three separate new gmails accounts to those 3 as recovery options for those accounts.  I hope CSA can help me. We are old people.