Jurassic World: Fallen Kingdom takes the franchise to some very new and interesting places, but some fans might have wished that it went back to revisit one character who never made it into the sequel. Jake Johnson's character of Lowery, the sarcastic tech guy in the control room of Jurassic World did not appear in Fallen Kingdom, but it turns out that at one point, he did. Producer Colin Trevorrow revealed that in a very early version of the story, the part of the character that became Franklin was actually Lowery. Unfortunately, it was decided that the temperament and attitude that was needed for that character simply wasn't a good fit for Lowery. According to Trevorrow...
There may have even been an early moment where Lowery was Franklin's character, because he potentially could have done that job. But he didn't quite have the same spirit. We did like the idea of [Zia and Franklin] being pretty idealistic young people who are activists who really believe in the cause that Claire believes in. I wasn't really able to shoehorn [Lowery] into that, he's kind of a cynical guy.
The character of Franklin Webb, played by Justice Smith, works for Bryce Dallas Howard's Claire for her organization that is working to save the dinosaurs. As the resident "computer guy" in the movie, he goes along with the group headed to the island in order to access the old computers that will allow them to find the dinosaurs they need to rescue. From that description, there's really no reason that the character couldn't have been Lowery. As the "computer guy" from the first movie, it would make even more sense to bring him along, as he had first-hand experience with the park computers.
However, it was eventually decided that it made more sense for both of the characters that Claire brings along to be more idealistic and committed to the cause. One doesn't really see Lowery as the sort who would follow Claire and go to work for what is essentially an animal rights group. As Colin Trevorrow tells Empire Online, he's a bit too cynical for that. Therefore, the character was changed to somebody who would match up with paleobiologist Zia (Danielle Pineda) a bit better. He's a young man who wants to help the dinos, even though he happens to be personally terrified of them.
Sometimes good storytelling just gets in the way of other considerations. There is absolutely some nice symmetry to the characters fo Franklin and Zia that wouldn't have been there with Zia and Lowery. While bringing Jake Johnson back would have been great, he was a highlight of the previous Jurassic World, he just wouldn't have fit in the story that was being told. We know there will be a Jurassic World 3. Perhaps the filmmakers can find a reason that works to bring him back for that one.