No, the CPU is still an 8-bit Z80. It does have an upgraded graphics card in an expansion slot with a Yamaha v9990 - the next version of the v9958 graphics chip built into all MSX2+ machines. Both chips have some clever display modes which can generate "16-bit type" graphics (really 15-bit + overlay (if supported in hardware)). Those modes work by using YUV-like encoding and are similar in concept to the Amiga's HAM mode. Remarkably advanced stuff for an 80s 8-bit home computer!
Sure, that was my takeaway too but my disliked half-arsed quip about graphics fidelity would apply to the 16-bit graphics aspect :)
I remember reading about MSX back in the old days, when I was transitioning from a Spectrum to an Amiga, but I genuinely had no idea how far that ecosystem evolved. A shame for it, and the Amiga, that they shared the same timeline as the in-hindsight-unstoppable MS-DOS PC-Compatible juggernaut... .
- ed: Turns out this one's a 16-bit machine? Anyway.