Well, the expansions for the first game were made by another studio, TimeGate. This was done because Monolith had a rather... bad... falling out with Vivendi during FEAR's development. They couldn't get out of it, but, they didn't want to work with Vivendi anymore. So, they finished the game and didn't want to make any further content for them. But, Vivendi owned the FEAR title, and Vivendi had already contracted for expansions, so Lith laid out a very basic story... and left. But, TimeGate ignored most of the story beats and did their own thing, and Vivendi was planning a FEAR 2 after they were finished. Telling new paranormal stories. While Monolith owned all character and locations. All the while Monolith were developing the official sequel under the title Project ORIGIN. But, then Vivendi fell apart, and during it's final days as it was selling off IPs... Warner Bros (who own Monolith) bought the FEAR title. So, Project ORIGIN became FEAR 2: Project Origin. So, in order to avoid confusion because Monolith were very unhappy with the story telling TimeGate made, they announced those expansions were not canon. Reborn was official canon because it was made by Monolith, designed to bridge the gap between FEAR 2 and FEAR 3. To explain how Paxton was back, and with Paxton back... it would explain how Point Man was drawn back to the city. Monolith wanted to use FEAR 3 as a means of really bringing the first two games closer. By bringing the main characters together. They wanted to expand the universe in the second game, show events happening in other locations while the Point Man was on his mission. And, to show more of Armacham and the people behind it. Also, you couldn't really have Alma get pregnant with her son Point Man as the main character in FEAR 2.