To be fair, regression to the mean could have you believe that Bo could very well work himself back into shape, and return to his "bad but good enough because he's a shortstop" defensive value. Naturally the projections don't have all the information available. Bo is entering his age 28 season, and this isn't normally where you'd expect defensive utility to fall off a cliff.
The Varsho projection on the other hand, makes absolutely no sense. Has to be an error in the inputs.