While he says that Instabridge is in a “difficult position,” he thinks that open sourcing Nova “has to be a component” of helping rebuild trust with the community:

Yea, I bet it is a difficult situation, wanting to add advertisements and trackers to an app you didn't develop while trying to skirt out of a public commitment for going open source, an act that would allow people to completely undo your efforts for ads and trackers. I can see why they don't want to open source it.

For context that is paraquoting Barry(the ex-dev that left) talking about instabridge and open sourcing it. the full quote is in the post.