Good thing is that the content is not lost for those that know to surf the web. But those locations don’t help reddit at all (main one is the wayback machine from archive.org and then there is a raw datadump of anyhting up to march 2023 as JSON)
you can use a secondary firefox profile. starting firefox with the --no-remote -p switches allows to load it alongside the main profile (-p loads the profile manager and --no-remote suppresses the “open new window in existing profile” behavior
Lets hope that federation gets a backfill/resync mode, too so first subscriber doesnt get a empty magazine/community.
or just go to archive.org and use the wayback machine. newer posts need some fudgery to find the comments since archiveteam snatches content right as it is posted and due to that comments are only reachable via their link