The news about All-Father Odin's elder brother had clearly been deliberately revealed by Hela. Her goal was obvious too: she wanted Robet to go after either All-Father Odin or that elder brother of his.
After all, just as Hela had said before, as All-Father Odin gradually aged and even neared death, Hela's seal would gradually break until she regained her freedom. In that case, would the elder brother who had also been sealed by All-Father Odin really not regain his freedom as well?
And when it came down to it, although Thor and Hela were both heirs to Asgard, All-Father Odin's elder brother was likewise an heir to Asgard. In fact, if All-Father Odin really had usurped the throne back then to obtain the position of All-Father, then that elder brother's legal legitimacy was even higher than Hela's and Thor's!
Therefore, Thor was Hela's enemy, and that elder brother of the All-Father was also Hela's enemy. If she could use Robet's hand to get rid of that elder brother, it would be the best possible outcome for Hela.
This was clearly an open scheme. All-Father Odin's elder brother had been sealed on Earth, so no matter what, Robet had no way to sit by and ignore it. Because All-Father Odin was already on his last legs, the seal he had set would inevitably shatter. It was only a matter of time before All-Father Odin's elder brother broke free.
And unlike Hela, who could send an incarnation to the Hell Dimension, All-Father Odin's elder brother could be said to have been completely isolated from the world. He had no idea that, after thousands of years, Earth had already undergone earth-shaking changes.
In that elder brother's understanding, Earth was still a pasture belonging to Asgard. He would not care about the lives