In the world of simulation, rear projected curved displays are fairly common.
They are done with edge blended groups of projectors and a lot of processing power behind the image and a willingness to tailor and re-scale content, and abandon, twist, and manipulate the addressing of pixels, all sorts of techniques, to get images looking good. Acrylic substrates for "semi-rigid" screens are common, and can be "cold formed" into spectacularly immersive displays. Nice long throws and high value added mirror systems are used.
These sorts of displays are not "Home Cinema" purposed, they are for problem solving, architectural planning, and training. So the functionality is totally different. I'm certain that a rear projection curved screen home cinema display is quite possible, but it would need to be a partnership between a screen manufacturer, a projector manufacturer and a skilled integrator, all funded by a patient and deep pocketed customer. Its a nice engineering challenge, but nobody is going to want to do it inexpensively. There are many hours involved in crossing all the "T"s and dotting the "i"s.