@quarnero,
Yes, you are right. This presentation shows that the i.MX 8 and i.MX 8X series are FD-SOI, but the i.MX 8M series is HPC.
That means that the i.MX 8M Quad could be made in either Giheung, South Korea or Austin, Texas, USA.
Unfortunately, this means that the i.MX 8M Quad isn’t as power efficient, but it should be a little cheaper to make, and it can more easily be shrunk to 14nm FinFET.