Short answer: No, Kaleb Johnson is not the projected starter — MarShawn Lloyd is. Here's the full picture from the wiki.
With Josh Jacobs on the Commissioner's Exempt List (placed Aug. 30), the Packers' RB room reshuffles like this:
- MarShawn Lloyd is the primary lead-back candidate. He's fully healthy for the first time in his career after missing 35 of 36 games his first two seasons, flashed in training camp ("looked like he was shot out of a cannon"), and the Packers have been preparing him as the Jacobs contingency. The wiki says he would "likely function as Green Bay's lead back" if Jacobs misses time (from the MarShawn Lloyd page).
- Kaleb Johnson was traded from Pittsburgh on the same day Jacobs was placed on the exempt list. He's listed third on the depth chart behind Jacobs and Chris Brooks. He struggled badly in his rookie year (2.46 YPC) and was third-string entering camp. He's a big, powerful runner with pass-protection ability, but he'd need to earn snaps over Lloyd.
- Chris Brooks is currently on the non-football injury list, muddying his availability.
The Fantasy Headliners described the Packers' situation this way: they view Johnson more as a change-of-pace option, noting MarShawn Lloyd is still in the mix for the early-down work Jacobs usually handles.
Bottom line for fantasy: If you're looking for the Packers RB to stash with Jacobs out, Lloyd is the priority target — he has the clearer path to a lead role and better draft capital pedigree. Kaleb Johnson is a deeper-league dart throw who needs to prove he's improved from a rough rookie season.