AD Sites & Services: Server Removal

Current environment:

• 5 sites
• 2 domain controllers in the primary site A
  
• 1 domain controller in each of the other sites B,C,D,E.  No other servers in sites B,C,D,E
  

Objective:

• Remove DCs in sites B - E

Questions:

1. Do the DCs in sites B -E have be DCPROMO'd out before being able to remove them from their sites?
2. If they have to be DCPROMO'd out before removing them from their sites, will the KCC automatically refer those sites to primary site A for AD services (authentication)?

TIA