Honestly — and this is really all I think I should say further on this — I see and even get the arguments you’re making here, but it reminds me of a discussion I had with someone at a Doctor Who meetup shortly after we first got a glimpse of “Presenting Sir John Hurt as the Doctor!”, but before the following season. A fellow I got to talking with about it went into excellent, detailed argument explaining why Hurt could not possibly be playing an actual previous incarnation of the Doctor whom we hadn’t been shown before.
The show did it anyway, of course. All the reasons in the world a given viewer might disagree with it didn’t change this.
The problem with the Titan, however, is when you look at the situation empirically, the Titan-A cannot possibly be the same ship as the Luna class from LDS, despite the dialogue calling it a refit, or however Matalas wanted to justify its existence.
Let’s look at the timeline.
2379: Riker get a new command, the USS Titan, in Star Trek: Nemesis. We don’t see the ship or know anything about it other than its name.
2380: We finally see the novelverse design of the Luna class Titan in Lower Decks: “No Small Parts.”
2381: Thaddeus Riker is born. Over the years he will have lived on several starships, implying that Riker & Troi left the Titan at some point after 2381 and that Riker captained more ships before retiring around 2391.
2396: The Luna class Titan is decommissioned and the Constitution class Titan-A is commissioned.
So here’s my question: Why would Shaw be complaining about having to purge his ship’s computers of Riker’s jazz music when Riker had no longer even been in command of the ship for at least 5 years, and at most 15? Wouldn’t the Titan have had at least one more captain after Riker, or likely a succession of them, before Shaw took command in 2396 (and that’s assuming the Titan and the Titan-A are the same ship?)
This is a situation of Matalas having his cake and eating it too. He clearly wanted to link his new Titan to the ship mentioned in Nemesis, despite the fact that it could not logically be the same ship. So he added some clumsy dialogue to try to make it all fit, but the evidence supports two different vessels far more than the dialogue implies.