I can imagine a series of useful threads always at the ready for onboarding new people.
But I hear you, ensuring new employees to feel warm and welcomed is crucial for every organization. Especially true for orgs that lean more remote.
Orgs can still use @random channels, @club-channels and you could set up an @annoucements to have spaces for fun links and bulletin materials, and other ways to get to know your peers.
@struct we lean pretty work-focused, we love building. But we should bring the fun too!