Which version of Movie Studio 16 did you buy? The product comparison here. The product pages here.
Which versions of MS 14 and MS 15 did (or still do) you have?
Also, which HitFilm plugins did you expect to have with your version of Movie Studio 16?
I have MS14, MS15, And MS16 suite. I also own total FX from new blue FX and it is no longer showing the plugins on MS16. I just deleted everything from my computer to attempt a completely clean download to attempt to get my plugins back.