Re: Let's not over-react here
It 'is' reasonable, but it should also be a choice. Forcing organisations, companies, etc.. to use a domestic domain, over which you have full control, is a simple first stage to suppress any opposition - you can refuse to issue a domain name or yank an organisation offline with very little effort.
Now you have control of the domestic DNS, so you start informing subscribers that you'll be changing their DNS and routing any mail through government servers.