AFAIU (hardware adaptation is not really my area): Mer/Nemo Mobile (and by extension, Sailfish, as the child of the parents) do not specify a single kernel. The kernel used is dictated instead by the hardware adaptation. There may be some demands on the kernel from other pieces of the stack (for instance, systemd is increasingly pushing to require newer kernel features), but with sufficient work, any kernel is usable.

I haven't looked, but I'd guess that the emulator is using the x86 hardware adaptation: https://build.pub.meego.com/package/...%3Ax86-generic