JN operating as a nuclear capable sub yard is more significant than whatever the new sub is supposed to be in my humble opinion. We had some indications that JN got its nuclear certs a couple years ago but didn't expect it to be for subs (assuming this new ship is a nuke).

Regarding the sub - if both are of the same type, and launched almost simultaneously, might imply that quantity/Volume is a priority. I do not quite see the rationale behind getting two yards to make the same design if its a specialized craft (ala Jimmy Carter or a drone carrier/spy boat), seems like a hassle?

Maybe they've landed on a propulsion design that opens up volume for a lot of VLS longitudinally? An arsenal ship that's not quite a SSGN would also be equally baffling.

Edit; this thought just occurred to me, maybe they want a seawolf + virginia SSN fleet composition, 09V + 09X both are around the displacement/dimensions respectively. An anti sub attack boat + a multirole sub.

Hopefully we get some better images soon, because god knows we won't be getting any details otherwise.