Quoted from Astropin:Nitro in Canada will be coming out with replacement I/O boards...when exactly I don't know but they did say they would be doing it.
Quote from them: "We'll also be making replacement IO boards for those in need."
The problem with reproducing the I/O boards (in my opinion) is that in order for a run of them to be feasible, about 200 of them need to be ordered. That means whoever places the order will need to front approximately $20k to start the run. This could potentially be negotiated to less. I'm not sure there is the appetite/demand to require that many.
If someone manages to get committed/fully paid for 200 boards, they are obtainable.