I think @sellwanger has confused what the IRS previously said in Rev. Rul. 2020-27 about the nondeductibility of eligibility expenses covered by PPP Loan which a taxpayer reasonably expects to be forgiven.

In any case, the guidance has been made obsolete by §276(a) of the COVID-related Tax Relief Act of 2020 and Rev. Rul. 2021-2.  Incidentally, that also has nothing to do with whether a loan, which has yet to be forgiven, should be written off the books.