I think just the opposite. Confidence is often the difference between a successful major leaguer and a failure. Anyone that is rated that highly in AAA is likely to have the talent to succeed. An early call up can be ruinous to that confidence for a kid that is not mentally or physically ready for the top competition. A three month success is hardly enough for most players to establish themselves in any league. A batting average of .278 with greater than 25% strikeout rate is hardly a sign that he had mastered the competition level in the various minor league levels.
Hopefully, the Cubs MLB team will be good enough in the future that they don't have to move