Like many, I thought the message was gonna be about the location of the Road poneglyph or a secret about Blackbeard’s anatomy. Although, I kind of like how instead of just being an informational plot point, it was more a sincere sentiment from a friend.
It tells us that Marco never flat out said no to going to Wano. Even though us readers and Nekomamushi seemingly agreed that he had a viable reason to not show.
I mean, Marco was on the losing side of two back to back brutal wars. Nobody would hold it against him. What’s more he decided he was going to go before the Shichibukai system dissolved and before the alliance between Big Mom Pirates and Beasts Pirates happened.
So it’s not like he changed his mind as world events unfolded. He made the resolve the moment he was asked.
This shows the kind of friend Marco is. And how he took Whitebeard’s final order to protect Luffy extremely serious. What a brother to Ace too, ready to fly straight towards the frontlines of his third war for those he loves.
So while I understand the disappointment it wasn’t a big reveal, I think it further characterizes Marco in a positive way. I loved how simple it was and how hard it hit, I can’t wait until he and Luffy meet up again.