Those were both limited-run (for now at least) offerings. They were reasonably popular, so who knows what will happen.
I purchased the SYS-MFT-FX set with my first MFT. I think it definitely makes the table far more useful, and having it all together helps with the "system" approach, and makes it more likely people will get the several components that make the tools easier to use. I find it definitely improved the comfort of my RO125. I bought a Domino since then, but find the ends of the clamping elements to be quite as well.
I bought a Seneca hold down plate + Kreg Automaxx clamp for use with the domino; but the regular quick clamps included in the set are certainly an acceptable hold-down as well.
I've used the SYS-MFT-FX far more than the fence, rail, and stops included with the MFT "set", even though I do have a track saw.