So, as we all know, Shanks is the person who brought back Loki to Elbaf after beating him.
And after 6 years, he was finally freed, by Luffy who is now another Yonko just like Shanks. So, what will Shanks think of this? Well, as we know from the very start of the arc, he takes protecting his allies and territory very seriously. We can see this when he rushed to detain Bartolomeo after Bartolomeo burnt a flag on his territory
This is of course similar to what we see from Shanks in chapter 1, where he talks about how he won´t tolerate any harm to his friends, however I think there is one difference
Shanks at first didn´t care about disrespect. Now he does. As far as we know, all Bart did was burn his flag and replace it with Luffys flag, he isn´t said to have hurt or killed anyone. So why does Shanks now care about disrespect? Simple, I think perception is everything, as he said, he doesn´t want people to lose trust in him, or for the world to think anyone can go and cause trouble in his territories. Look at Oden for example, when he returned to Wano, he was seen as the hero that would save the country from Orochi. However, after he began dancing half naked in the street, much of Wano lost respect for him and the country essentially became Kaidos. Also, I think there´s one more reason Bartolomeo had to be dealt with, so much so that Yasopp decided to finish him off.
I think its interesting to think that the RHP were at first looking for Blackbeard at Wano, and some of them decided why not visit Luffy, but Shanks decided to focus on Bart instead, weeks after he burnt down their flag. Imo, this is because Shanks realized the era was changing fast, and he went from the newest Yonko pre time skip, many decades younger then WB/Kaido/BM, to being the longest reigning Yonko. Now that Big mom and Kaido had fallen to the new generation(and around the same time, the revolutionary army is having huge victories against the world government) pirates were coming to take his spot. Bart is only just the start. While he wasn´t acting under orders from Luffy, it is worth pointing out that Luffy does indeed plan on taking down Shanks, just not first.
And if you look at the pattern
FMI: Big Mom doesn´t have beef with Luffy until he comes to mess with her business on FMI
Ph: Doffy doesn´t have beef with Luffy until he kidnaps Ceasar
Dressrosa: Kaido doesn´t have beef with Luffy until he destroys his Smile factories
could the pattern continue with Shanks not having beef with Luffy until he decided to free the most dangerous criminal on Elbaf, an island associated with Shanks? Could this be why we didn´t get a Shanks and Luffy meeting on Wano after Luffy became a great pirate? Because they might meet on bad terms on Elbaf?

And after 6 years, he was finally freed, by Luffy who is now another Yonko just like Shanks. So, what will Shanks think of this? Well, as we know from the very start of the arc, he takes protecting his allies and territory very seriously. We can see this when he rushed to detain Bartolomeo after Bartolomeo burnt a flag on his territory

This is of course similar to what we see from Shanks in chapter 1, where he talks about how he won´t tolerate any harm to his friends, however I think there is one difference

Shanks at first didn´t care about disrespect. Now he does. As far as we know, all Bart did was burn his flag and replace it with Luffys flag, he isn´t said to have hurt or killed anyone. So why does Shanks now care about disrespect? Simple, I think perception is everything, as he said, he doesn´t want people to lose trust in him, or for the world to think anyone can go and cause trouble in his territories. Look at Oden for example, when he returned to Wano, he was seen as the hero that would save the country from Orochi. However, after he began dancing half naked in the street, much of Wano lost respect for him and the country essentially became Kaidos. Also, I think there´s one more reason Bartolomeo had to be dealt with, so much so that Yasopp decided to finish him off.

I think its interesting to think that the RHP were at first looking for Blackbeard at Wano, and some of them decided why not visit Luffy, but Shanks decided to focus on Bart instead, weeks after he burnt down their flag. Imo, this is because Shanks realized the era was changing fast, and he went from the newest Yonko pre time skip, many decades younger then WB/Kaido/BM, to being the longest reigning Yonko. Now that Big mom and Kaido had fallen to the new generation(and around the same time, the revolutionary army is having huge victories against the world government) pirates were coming to take his spot. Bart is only just the start. While he wasn´t acting under orders from Luffy, it is worth pointing out that Luffy does indeed plan on taking down Shanks, just not first.

And if you look at the pattern
FMI: Big Mom doesn´t have beef with Luffy until he comes to mess with her business on FMI
Ph: Doffy doesn´t have beef with Luffy until he kidnaps Ceasar
Dressrosa: Kaido doesn´t have beef with Luffy until he destroys his Smile factories
could the pattern continue with Shanks not having beef with Luffy until he decided to free the most dangerous criminal on Elbaf, an island associated with Shanks? Could this be why we didn´t get a Shanks and Luffy meeting on Wano after Luffy became a great pirate? Because they might meet on bad terms on Elbaf?