I maintain a paid Chrome extension (https://chrome.google.com/webstore/detail/shortkeys-custom-k...) and I've had a very similar experience with the frustrating repeat automated shutdown emails, except that so far my extension hasn't been actually shut down. I'm just waiting for the day that it happens at this point. I'm surprised it has not happened before now, since my extension requires a lot of permissions to do its job.

In my case, I make a nice little side income from that extension so it would be a noticeable income hit. But I'm not sure of anything I can really do to prevent it from being shut down if and when Google's robots decide the time has come.