The numbers mean nothing as far as the number of MP a lens can resolve, and can not be extrapolated. The resolution will increase on a camera with more MP, but at some point, any improvement is very slight.
Aside from the fact that lens resolution is not measured in MP, the tests are run on a particular camera and only apply to that camera. Thus, to get a meaningful measurement, you would have to put it on a XX mp camera and check the resolution to see what it was on that camera.
Your best bet is to view Canon's calculated MTF curves. The center will be excellent, of course, but as you move toward the edges, things deteriorate.
As you get sensors with higher numbers of photosites, diffraction starts at wider apertures, so that means you cannot resolve each pixel sharply unless you use wider apertures. This is a big factor in resolution, maybe more than the resolution of lens itself.
Since its a f/4 lens, at f/4 on a 36 mp FF body, diffraction would have just begun to have a tiny effect at f/4. At f/8, it would be significant, but not a big issue.
I wouldn't worry about it until you got a 120 or higher MP body.