@Solid:
is that aimed towards me? because it just confirms what I was saying.
The setup is clear, how you evaluate and interpret that setup is up to you, meaning what direction it shows, because the execution and lack of build-up arguably feels lackluster in regards to Yamato, but you can also argue that with build-up the twist of being Oden fanatic and female would have been revealed.
What Luffy has been great in is helping the respective Strawhats, for the most part at least, overcome their traumatic experiences of the past and possibly even draw strength from it, he is either a therapeutic or liberating entity for them. Brook and his loneliness of 50 years were swept away instantly by Luffy´s acceptance of him despite his appearance, something Brook points out as well, especially after Luffy states after meeting him that he will get his shadow back for him, Nami and her experiences drawing maps in that room, Robin´s fear of getting betrayed by people she finally cares for for the first time after 20 years after Ohara and so forth. The only exceptions are Zoro and Usopp really, or at least you would need to do a thorough analysis with that setup in mind, and even then it probably would require some heavy interpreting.
You can argue that Luffy easily destroying the shackles is along those lines as well even if it´s a bit on the nose due to the obvious figurative meaning, Yamato is waiting for 20 years to remove them, and Luffy comes along and does it almost immediately.
A counter-argument would be how nonchalantly this has transpired, even with a comedic tone at times. Yamato explains everything herself without any real build-up in a near monologue, then Luffy casually says he will remove them, and does it, Yamato is seen crying at her father´s treatment, but it is overshadowed by everything else happening, meaning her trauma is not really underlined sufficiently enough, at best it is implied and stated, but the audience does not really feel it due to the tone.
So it might feel like it´s not befitting a possible Strawhat.
The closest we have who had a similar introduction, albeit in a much smaller setting, is Brook. His introduction, while either hinting at possible traumatic experiences (his first death and loss of crewmembers) or has him state them similarly to Yamato nonchalantly and even in a cheery tone (something Sanji even points out).
Only later we learn how lonely he really was, how heavy the burden he carries is, and how liberating Luffy´s behavior towards them truly was.
Basically this page summarized it completely.
So if Oda handles Yamato in the same vein, i can see the lack of sad and emotional tone in her introduction and when she talks about her experiences of the last 20 years as just hinting at a sad backstory, and something that will get illuminated later on, or rather it needs to be.