Replying to myself with additional information from the IRS. This appears to be the answer, but I'm not sure I trust it.
In a March 30, 2021 bulletin, the IRS wrote: (see https://www.irs.gov/newsroom/emergency-aid-granted-to-students-due-to-covid-is-not-taxable :(
"Emergency financial aid grants made by a federal agency, state, Indian tribe, higher education institution or scholarship-granting organization (including a tribal organization) to a student because of an event related to the COVID-19 pandemic are not included in the student's gross income.
Also, students should not reduce an amount of qualified tuition and related expenses by the amount of an emergency financial aid grant."
[my emphasis]
