I'll throw in my two-cents and express my confusion at the lack of civilian vessels available in plastic - Oh BOY, not another one...
Obviously some ships won't fly off the shelves, but I can't help but find the lack of some to be distressing. Revell's Olympic is a good example; why they didn't maximize potential and offer a WW1 variant I have no idea - nevermind reintroducing it to the range for those that are now facing crazy prices on evilBay. Heck, why didn't they alter the Titanic tooling once more and offer Britannic? Easy enough to bash the hospital ship I know, but anything White Star or Titanic related sells. Maybe a little Normadic to go with the various offerings? Tiny starter kit, not too expensive.
Lusitania is another famous one they've never done. I know of the super rare 1/350 kit, and a old resin example from Bang Models, but again, not widely available. Combrig made one very recently in resin but I can't find one for love nor money... that says a lot about the alleged lack of demand, I think...
To crossover to another subject of modelling: the amount of random WW2-era aircraft I've never heard of (and I used to be an aircraft modeller!) that the countless Eastern European companies have made is crazy. In railways too: the amount of super niche things being released despite lack of interest... I recall seeing an announcement from a major retailer about how one company were upsizing a shunter they made in 00 gauge, to 0: 1/76 up to 1/43. Big money... and had something like 13 likes after a week. They're still manufacturing the thing. Why? Nobody wants one.
To be fair to myself ship modelling isn't the most popular form of our art, with civilian subjects being lesser still. Alas, some representation could go a long way, especially with the ship nerds and enthusiasts that seem to be prevalent on many platforms - the posts and pages I see on Instagram about liners old and new are countless, not to mention on YouTube.
I reckon it's worth a shot, ModellbauRay on IG made a resin 3D printed Wilhelm Gustloff kit last year in 1/700, and has expressed the possibility of releasing the Vaterland. Now imagine if that was plastic from a major manufacturer: If that's not demand, I don't know what is!