Yeah, I think the Franklin was a testbed for the NX-01, maybe originally the NX-Epsilon or NX-0.5 or NX-F (if they are using a phonetic alphabet for pre-numerical registry). Just like Edison and his crew, it was later polished up and tossed into the new peaceful, exploratory Star Fleet, even though that's not what it was built for. The NX-326 registry just shows us how many old ships they re-registered for official use, and the "Freedom class" may have been a new moniker for what was previously "NX testbeds."
I like to think the NX class was renamed. Perhaps to the novelverse Columbia class, or perhaps to something else.
I like to think the NX class was renamed. Perhaps to the novelverse Columbia class, or perhaps to something else.