The answer to this question was found in the WDW Annual Passholders group, and I'm sharing it here:

"They are undermanned because of the rules in place that they have to be vaccinated. That way they can protect the vaccinated from the unvaccinated and in return protecting the unvaccinated from the vaccinated who are also at risk of spreading it to the natural immunity community, who are trying to keep safe from the unvaccinated as well all while the vaccinated are just trying to protect their unvaccinated younger family and friends who are trying to protect themselves from the vaccinated while they are talking to unvaccinated or natural immune future guests over them phone."

It's so simple when you step back and just think about it. Come on, man!