Ignoring the fact that the projector doesn't get to true black (noted by smusamashah), and supposing there's no diffusion that spreads the light of a pixel out to surrounding areas of the display panel, it would be possible to say that the display has infinite contrast, I suppose that is true.

Contrast is important, but alone it is useless. You could have a display with only two levels: black and white, and if the black is perfectly black, then it's infinite contrast (any level of white, no matter how dim, is infinitely brighter than total black), but 1-bit color would be useless in reality for home theater.

To make infinite contrast useful, it's necessary to have HDR as well to take advantage of having very dark and very bright areas both able to be represented with detail. Plus having sufficiently bright maximum brightness so that the brightest highlights can really shine.