Rebs Gaming has made a big video about Halo Campaign Evolved.
He claims that Abstraction Games is the big game developer who partnered with Halo Studios to make the remake.
To quote Rebs:
They (Rebs’ anonymous source) say Abstraction is responsible for level and technical design, specifically full development of campaign missions, including concept design, level blockout, polishing, creating scripted events and retuning combat and gameplay to account for new mechanics and features such as sprint and four-player co-op.
Abstraction previously worked with Halo Studios to add accessibility features to Halo: The Master Chief Collection two separate times in 2021 and 2022.
Rebs’ sources also claimed that Abstraction and Halo Studios worked on Halo Campaign Evolved starting 2023. While three years is a short time for development nowadays, it’s enough for a remake.
If Rebs’ rumors are true, Abstraction probably also made the new missions set just before the events of the game.
Abstraction’s gameography includes Baldur’s Gate 3, Mass Effect: Legendary Edition, Duke Nukem 3, Hatoful Boyfriend, Hotline Miami, etc. So they’re as good a partner as Halo Studios can get.