Gulf Coast Hurricane Aid Act of 2021 This bill provides emergency assistance for disaster response and recovery, and for other expenses, directly related to Hurricanes Laura, Delta, or Zeta. Specifically, the bill appropriates funds to the Community Development Fund for necessary expenses related to disaster relief, long-term recovery, and restoration of infrastructure, housing, and economic revitalization in areas in states for which the President declared a major disaster. The bill further provides for the use of proceeds from a system of competitive bidding to award licenses in the band of frequencies between 3700 megahertz and 3980 megahertz, to be deposited in the general fund of the Treasury and used for emergency assistance.