Not even soldered, they could came up with some fancy marketing name for slowest SSD drive in their line up (lets call it eSSD) and just drop-in 2.5" SATA SSD for $20 (retail cost of 120GB SSD on Amazon) instead of spinning rust. No need of redesigning chassis, no need of changing any factory procedures, machines, robots etc. Just give a box of SSDs instead of HDDs to the person that is responsible for putting them in. Here, job done, and Apple could "brag" about having SSDs in entry level options. Standard SATA SSD would increase massively performance on those machines.