This is a Myth, Not a Cause for Alarm
Currently, there is no scientific evidence that any exosuits have caused muscles to atrophy. Especially with unpowered exosuits like the Apex, the workers still do a good amount of the work with their muscles. Even with exosuits, these jobs are still physically demanding.
A nice summary can be found in a 2010 publication by Krogh-Maden et al. in the Journal of Applied Physiology: “…most literature suggests that reduced muscle loading must be drastic, such as limb immobilization or bed rest, to observe muscle atrophy.”
The evidence suggests that the real issue is with extremes: far too little or far too much muscle activation can lead to muscle atrophy. So, overexertion can actually lead to weaker muscles or injuries that lead to deconditioning; but for a large intermediate range of activations, muscles have been shown to maintain their mass and not atrophy.
Evidence suggests that exosuit technologies may actually help workers stay within this healthy intermediate range of musculoskeletal loading.