Display that supports full CIE xyY color space
No, most likely these kinds of displays do not exist, at the time of writing this post. Although the negative is hard to prove. And in this case i don't have deep enough understanding of the lore.

Reason for me saying this is that usable displays need some serious miniaturization. The miniaturization process is quite expensive and requires some serious investment. There should be quite massive patent trail if this was indeed true. So we should look in patent databases for this trail.

Second, having such tech probably will not yield full color space, at least initially. Because the filter can only filter out colors that the back light can generate. Most probably therefore this is some kind of projector technology at first. Also filters probably have a practical limit to how much they can be tuned.

Third, if/when such tech is available it must recuperate the development cost by selling enough units to overcome the capital investment. There is a likelihood that this is one of those things that can not be produced without the miniaturization step like digital cameras. So keep a lookout for a killer application for this tech.

Some major downsides of this kind of tech is the fact that you filter out light. This means it eats up part of the energy input. This leads to a heat dissipation problem, which for perfect narrow band filters is actually pretty huge part of the emitted light. Lot of energy goes wasted, and needs to be engineered around.