Yeah the ship registry numbers are old as well, it could be that there was another earlier ship with the 1031 and 1030 designation and when they were decommissioned the new ships gained their registry.
Before now it's only been the Enterprise 1701 that had that honour.
Another possibility is that there are two ships with the same registry out there and Section 31 has borrowed their registration for secrecy purposes.
Happens all the time with cars and boats.
I thought NCC registrations were considered not indicative of order built? Otherwise there would be many inconsistencies.