Content from another instance only shows up on lemmy.world and you can only participate there with your lemmy.world account if the other instance federates with lemmy.world. Beehaw is not a fan of the higher moderation workload with the influx of lemmy.world users, whether they’re real people or bots. That’s why they decided to stop federating with instances with open registration, like lemmy.world and sh.itjust.works. Some people are pretty upset about the decision while others show more understanding or even welcome the step by the Beehaw admins.