Might be unpopular opinion, but I don't think this radio silence is ok at all. People paid money, so it's a responsibility, not a fun little side-project done at leisure. Setbacks are fine, lack of communication is not. All the author's going to succeed in is making people less likely to back any possible future project of theirs, or just ks projects in general.
I hope that everything's well as much as anyone but, yeah.