I have had two different conversations recently with other cyclists who both assumed no one carried spare tubes when riding on tubeless tires. In both cases, their desire to run tubeless was centered around this as a benefit. One person even compared them to run-flats on cars, where you'd still be able to ride it home.
I have definitely gotten fewer flats with tubeless, but I actually carry more stuff now than I did when I was running inner tubes. In addition to the same spare tube and CO2, I carry a second tire lever and a dynaplug kit. I also carry two CO2 cartridges where I used to carry one - as I worry that if the plug doesn't work, I'll need a second shot to inflate the tube.