Will the community survive? Probably not.
Most online communities have one real driving force behind it. And you have missed the opportunity to hand the baton over to other people.
It’s the conversation that is normally missed out and it makes such a big difference and identifies so much more than you can write down.
This happens a lot in organisations when someone moves jobs, it’s only an afterthought.
There becomes a Knowledge Gap. I heard that it normally takes 18 months for a new employee to become profitable to the organisation and for them to be fully integrated with the way of work.
Can you afford that time delay in an online community? And would the members be happy with someone new just turning up without an introduction?
If you get a chance just do a search on Knowledge Retention and Transfer. There’s some great stuff out there that will help you start the conversation if your community manager is about to move on.