New MacBook Air cheaper because of slower SSDs?

Well I certainly did not see this coming. Last year MacBook Air and rMBP had class leading SSD speeds.

Copying 6GB of files and folders took 28 seconds on last year's 11-inch MacBook Air, but took nearly twice as long (54 seconds) on this year's 11-inch model. With solid-state storage, lower capacity drives are often slower performers, and last year's 11-inch had the higher capacity 256GB of flash. However, the new 11-inch model was also slower than last year's 13-inch model with 128GB of flash storage.

SOURCE