I don’t think we’ll have Google Calendar’s level of flexibility anytime soon (potentially ever), so I’m hesitant to provide a timeline without knowing we’ll resolve your problem.
We also face a more challenging situation in that you need to promote the event through various channels, and it’s unclear when to do so.
I would suggest building an external flow (in Zapier or Make) that, when an event ends, fires a webhook and then creates the next month’s event. If that was interesting, we could look into making that webhook. This would be a much shorter timeline.