Y'know, I think it'd be neat if they could come up with a way to incorporate civilian shipgirls like this into Kancolle. Not as many famous historical ones, and most of the ones that are famous are famous for tragic reasons, but it'd open up new avenues for art.

In game terms, such ships could be represented as item cards, like Mamiya, giving various bonus abilities based on their historical role. I don't know the game mechanics well enough to speculate what sort of things could be interesting without being game-breaking - buffs to expedition rewards or XP gain, maybe?

Titanic herself, alas, is a bit early for Kancolle - so far they've only used ships that were in use in the WW2 era - but now that Kancolle has been opened up to Allied fleets, you could get girls like the Queen Elizabeth (used as a troop transport).

If you add it, they will collect. Games like KanColle are made for completionists. It doesn't matter if a ship is totally useless or completely statistically identical to dozens of other ships they already have, players will still play an event stage 20 times searching for the newest destroyer girl.

KanColle also already has a Shinkaiseikan version of a transport ship, plus routine quests to sink them. (Usually in Orel, much to Dechi's dismay...) It's hardly like adding in a mirror image wouldn't fit.

They could do what they did with Akitsu Maru, Hayasui, or Taigei, and add in special expeditions or possibly branching conditions in events that rely upon the presence of a "freighter" class ship. It would honestly make a lot more sense if they had a bunch of expeditions that rely upon transports with escorts than making basically every resource transport expedition rely upon destroyers.

They could even have special maps for it, where, rather than a boss node, they have a "destination node", and you only win if you get a certain number of transports to the goal line. Make a fleet with three transports and three of whatever else, and survive to the goal.

For the most part, however, I presume the reason they haven't done this is that half the selling point is the sexiness of military hardware, so rusty tramp freighters don't feed the desires of those who like the military history aspect of KanColle. (And there's plenty of other material for cute girls for the people who just want the cute girls.) The various freighters are also so diverse as to be hard to keep up with, and if used as proper ships as I was saying before, would just exist for the purpose of changing who went on expeditions, and largely be completely fungible. (Akitsu Maru had a sister ship, and there were plenty of oilers and submarine tenders, but they're not in a rush to come out with more ships of identical function...)

My lady Titanic.