It's a good thing they already have met Shioi, otherwise they would confuse the Bureau of Kanmusu Affairs Fleet Coordinator Nagato (presumably the spirit of the WWII ship--I guess getting nuked counts as dying in battle? But she did survive the first nuke, so one could say she was fighting for her life then) with the Fleet of Fog Fleet Coordinator Nagato.
Sadly, I assume Mutsu is in Hel, as sinking due to alleged sabotage doesn't count, but she might get to Return, since Hel is under new management these days. But then there wouldn't be cute Mutsu/Nagato interactions.
Fleet of Fog Kongou vs. WWII Kongou would be amusing. ("BURNING LOVE!")