[2023] Secret Image in event screen?

So I was playing Halo Infinite and when I opened the battle passes I saw for a split second an image that was replaced. I clipped it and looked through it frame by frame and saw a red spartan holding a shotgun(Sarge?). Is this something coming in the future or is this artwork of something similar to how the halo reach art shows on the season 1 battle pass. Sorry if this is old news but I’ve seen no one talk about it. I’m hoping it’s an RVB cross over to celebrate the new and final season.