Keeping this brief, I think it's worth considering that the Hito Hito no Mi Model: Nika is an impressive fruit, which lends more credibility to the idea.
To make this comprehensible, I will present all the manga panels and provide a concise concluding statement.
Roger expresses his wish to have encountered Joy Boy after discovering the "One Piece" (ch. 967).
When he returned from Laugh Tale, Shanks was told something by him (ch. 968).
Roger imparts to Rayleigh that it will be his son who will arrive at Laugh Tale (ch. 968).
Confirmation from Who's-Who is provided that Shanks has taken the Gum-Gum Fruit, as stated in chapter 1018.
In Chapter 1, Lucky Roo admits that they took fruit from a rival vessel.
In Chapter 1044, one of the Bald Gorosei declared that it would be impossible to restore the fruit.
Shanks and his crew spent over a year taking refuge in Foosha Village (ch. 1).
In Chapter 1, Shanks makes it evident that he has an aim or purpose.
In Chapter 551, Roger entrusts his offspring to Garp's care.
In Chapter 551, Garp departs from Ace and afterward Luffy, leaving them with Dadan on Dawn Island.
Luffy being entrusted with Shanks' hat at chapter 1.
Shanks recounted that Luffy had uttered the same words that former Pirate King, Roger, had spoken (ch. 506).
Momonosuke reveals that Zunesha was a friend of Joy Boy according to Chapter 1040.
At fourteen, Zunesha declared that Joy Boy had come back (ch. 1043)
With the applicable panels laid out, what are the implications?
From my perspective, it is difficult to understand why Goda does whatever he wants; however, I believe that my opinion holds some validity.
To start off, Roger comes to Laugh Tale and finds out the factual story; it's likely that he also comprehends the real nature of the Gum-Gum fruit; that being the Hito Hito no Mi Model: Nika.
Once he was back on the boat, he shared some confidential details with Shanks without any speculation as to what they were. Roger then proclaimed that it would be his offspring who would locate Laugh Tale and the riches that were left there. Subsequently, we are aware that Roger went ashore to have a baby with Rogue, and subsequently surrendered himself to the World Government in order to pass the torch to the new generation, but not before leaving Garp with the responsibility of looking after Ace, thus concluding the life of the initial Pirate King, Gol D. Roger. Garp gave Dadan on Dawn Island, East Blue, the primary responsibility of Ace's care.
At present, Shanks is stealing the Gum-Gum fruit from Who's Who, which is evidently a remarkable item and CP9 were responsible for escorting it. I would venture to say Shanks was familiar with the significance of the fruit. He eventually arrived at Foosha Village and made various trips in the East Blue, suggesting he had a purpose for staying there for a year. As widely known, Luffy ended up eating the fruit and Shanks made a wager of his arm with Whitebeard, referring to it as a "bet on the new age."
Luffy is left with Shanks' hat and the mission to become a renowned pirate as Shanks departs. It's peculiar that Shanks quickly vacates the scene right after Luffy consumes the fruit, as it counters his original plan.
The events of Chapter 1044 caused Luffy to become Joy Boy, due to the awakening of the Hito Hito no Mi, Model: Nika. In order to carry out what Roger had desired, Shanks stole the fruit and traveled to the East Blue to seek out Ace to offer him the fruit.
Despite the fact that Luffy had consumed the Devil Fruit, Shanks still rescued him and Luffy echoed the same words as Roger; this led Shanks to determine that Luffy was capable of inheriting Roger's ambition and carrying out the Will of D.