Maris, I am sure that these very points will be raised and discussed in the course of the exhibit. But...
Can an artist be legitimately credited with a work that they didn't personally make and cannot, even in principle, experience?
What ever is done in their name the blind "photographers" themselves have nothing to answer for. And if they bring questions about execution and attribution into the minds of their exhibition patrons they will have done something very creditable indeed.
... first of all, I do not have the impression that all of these artists (nor some mentioned in this thread) are completely blind; there are all manner of disorders of the visual system that would still permit a person to compose in an unusual way, whether on ground glass or with a loupe or similar devices.... even if they are 'legally blind.' For example, I recall a contestant on a recent US talent show who had something like a 1 degree field of view. Now, his talent was not photography, but... you get my point

It is possible.
But let's take the extreme case and suppose that a person were completely blind, i.e. totally insensitive to light. I suppose that person could still produce photographs with real meaning and artistic ownership.
The way I see it, we fully-sighted people make our photographs by relying on feedback... through the lens, through a viewfinder, through ground glass, or shooting from the hip with no viewfinder at all... whatever. All of those are well established ways of producing photographs. Why couldn't a person rely on the the other senses to roughly form a composition and then rely on feedback from others to determine whether that photograph was successful? And don't we fully-sighted individuals also ultimately rely on feedback of others if and when our work does go on display? Anyway, if a fully-sighted person did decide 'audience be damned' and simply shoot entirely for him/herself, then what is the print but a meaningless piece of paper? So feedback is intrinsic to the printed art.
Another interesting question I think this raises is to what extent all the rules and regulations of modern photography might actual impede our ability to record an experience in raw form. I don't just mean rule of thirds and sunny 16 and all that... I mean, how we decide, on the spot, whether a photograph is 'worth' taking.
You know, these days, sports photographers sometimes wire up several cameras with pocket wizards and fire them opportunistically. They are anticipating interesting perspectives. Success isn't guaranteed.. but is it ever? That's not my thing, but I do sometimes 'wing it' and photograph without composing, especially when using my mini-tower tripod, which places my camera ~30 ft up. More commonly, my camera is simply too high up on a normal tripod for me to seal the deal with a loupe or normal viewfinder. Now, I've gotten some pretty nice results that way. For me it is an issue of imagining the result and then enjoying the new perspective, whatever it may be. Granted, I get to view the neg/slides afterwards and sort keepers from trash, but... I could learn to give that up, I think. I suppose that I could conclude that the act of imagining the scene was enough for me and the act of accepting the result is for the audience.
Finally, I don't think that pre-visualization has to be done with the eyes open, I have a large number of anticipated photographs I'd like to make of scenes that I haven't actually seen. Did you ever imagine a particular landscape and then wonder where you might find such a thing? I don't think this is so unusual, actually. It's as natural as dreaming.
So, I see your point(s) but... I think there's quite a bit more to this. At least for me, it raises many questions about what composition really is.