I saw readings of the Hunter Foster BONNIE & CLYDE several times over the years and can also attest to its excellence. In at least one--probably more--Marc Kudisch was a very funny J. Edgar Hoover(occasionally in drag). Foster's sister was Bonnie in at least one of the later readings. Rachel Coloff--always a terrific perfomer--was often Blanche.
I agree that if it is no more, it is very much a shame. At least Yeston's PHANTOM gets produced everywhere but Broadway.
ironically, I did see a staging of Wildhorn's BONNIE several years ago in Chicago and recall very little about it.