I always liked the progressive nature of the TTs originally, but a lot of folks complained about it at the time with Shores of Gold. Which is why the next ones were not locked into a particular order despite the story still unfolding progressively. They went back to progressive style in Pirate's Life again, so I do personally find it a bit of a shame that the whole series isn't just setup in a progressive style requiring completing the earlier parts of the story first. It makes for a disjointed experience for newer players for sure.
But I also don't see any of it changing. They'll let you kick of Pirate's Life whenever you want so you can get into the Disney tie in immediately (though need to do it in order there) or start with Shores of Gold, or skip to either Seabound Soul or Heart of Fire (or swapping those two around since one does not require the other) as it is now.
Ideally though, it would be: Maiden Voyage, Shores of Gold, Ashen Age, and then Pirate's Life in that order.
Thankfully I personally played them all in the right order, and whenever I go back to it all I tend to just rerun the nearly full thing in order again (I do skip the Maiden Voyage since I have that all done and it is more of a tutorial than anything).