This is why it's important, as a group, to roll your server. Own the infrastructure of communication and discourse. To utilize open standards for which you or anyone else can create and run their own server, or client. Protocols should also evolve, or have organized successors over time. If you do provide backward compatibility, please do the best reasonable effort at making backward features work.
I feel like someone stopping maintenance of a private server is way more likely than the most popular chat client at the time shutting down eventually. In your mind, who in 2017 was still using AIM, blissfully unaware of the shutdown, only to be met with an error page and the loss of their friends forever? I'm sure most people are like me... over a decade ago, my AIM friends mostly migrated to text messages (and a fe…
>someone stopping maintenance of a private server
Would only mean that that specific person was unreachable. Everyone else could carry on like nothing had happened.