This doesn’t really seem like something to pin on the app exclusively - it’s a change management failure on the part of the party, underlined by the fact that even their normal phone lines were overloaded due to new data reporting requirements.
I wasn’t on the ground or anything (I’m a complete outsider who read the news) but this seems like a lot to pin on some app developers when the issues were spread pretty far. It’s damnably hard to train 1800 users spread across a state with varying levels of experience.