If the vinyl is a "full Bond" and in good condition just rough up the surface. Damp mop to remove the dust and go. If it is a perimeter bond remove completely. What is under the vinyl Wood? Concrete? The EasyMat is an alternative to backerboard over wood. It is also a creck isolation where ever you ust it. The sound reduction is an IIC or impact insulation. The best feature is that it is a bonded system not one that un couples.
If you are over concrete you can rough up the vinyl and go right over that. Abe sure to use a good quality TS. FlexBond would be a great choice.
Holy Freaking Orange Apron Nonsense. George, Remove the vinyl. Better yet, Get someone to set your tile that isn't "wondering" if you need to remove the vinyl.
Now what's under that vinyl, a wood framed structure or a slab? Is there a basement or crawl space under? That would indicate a wood framed structure. If it's the upper floor of a condo or high rise, it might be lightweight concrete, which is an entirely different animal.
Don't thank Joe, he doesn't know what he speaks of, at all.