After the success of the Fallout Tv series on Prime Video, it's no surprise that Microsoft and Bethesda would be looking for some way to tap into the success and popularity that the series has brought them recently.
The Tv series had become the number one most watched show on the Prime Video Service for its unique storytelling as well as the respect the show displays for the lore of the franchise. It wasn’t just the series that became extremely popular though, the Fallout Video Games also saw a massive surge in players across the entire franchise, with Fallout 76 reaching over one million players in a single day.

On May 17th, 2024, the official Fallout account on X announced that they would be doing a crossover with the massively popular game Fortnite. Details of what the crossover would look like are still rather unclear, but it's safe to assume we'll be hearing about it in the near future, possibly at the Xbox/Bethesda/Activision showcase in June.
Some speculation on what the crossover may look like suggests that they may be adding some of the popular Characters from the series such as Lucy or the ghoul Cooper Howard. Personally, I think there's a good chance that Epic games will introduce power armour into the game due to the fact that the image posted displays said power armour.
All we can do is wait and see, but I'm sure Fallout and Fortnite fans are excited regardless.