If you're playing with strangers, you'll find that after every mission, at least one player will just leave the hub. No dance party.
After promoting my Dwarf, I went into a Deep Dive with randos. After pulling off two stages with them, I popped the question on chat. I asked if we can throw a toast to some good music.
Turns out, a team of dwarves is more likely to stay together after completing three successful missions in a row. Key is asking nicely.
Or, you know, you could just ask your friends...