It's an interesting bit of data, especially because it includes all expansions to date. You wouldn't ordinarily expect a newly introduced character to have the third highest line count after 10+ years of expansions.

The most commonly used words is also interesting. A number of older characters seem to bring up the Warrior of Light as their most commonly utilized phrase, while that has shifted towards WL when you look at some of the prominent characters from this expansion. It reflects the abrupt shift in protagonists.

It's not surprising that if you build a ten year series around one protagonist (the player character) and then suddenly switch the entire story focus over to a freshly introduced one, there is a very real risk that your audience won't feel the same connection that they did previously. They gambled and failed. The problem is that the writers keep doubling down on it.