It wasn't accessible a year or so ago when I tried it. Maybe that has changed, but I've generally found that if an Xbox app is inaccessible, it stays that way. We're not a big enough demographic on the Xbox to change that.

I suspect many of these apps just render to an OpenGL/DX12 canvas of some sort, so they can run their codebases on whatever console/device they want to port to by just swapping out the graphics/drawing/pointer interface code. And that's not going to change, because there aren't enough of us on these niche consoles/devices to warrant specific ports for whatever accessibility APIs they might have. And I think the Xbox and Android devices are the only ones with anything approaching accessibility APIs.