Mike Zunino was rushed as well by a Seattle organization notorious for poor player development, making his MLB debut at age 22 years, 79 days, in contrast to Swihart's debut at 23 years, 29 days (Jarrod Saltamacchia made his MLB debut on his 22nd birthday).
It's not as if a single rogue projection is down on Blake Swihart. ZiPS, Steamer and FanGraphs Depth Charts are all bearish on Swihart, ranking him behind Zunino in the near future, including significant disparity in defensive abilities.
Indeed, projections are often wrong. Swihart could be better -- or worse -- than the current projections.