You do a good job of evading the basic issue of the "IRS use of the word "you" and the only reason for the Recovery Rebate Credit exists is for people who would be eligible in 2021, but an advanced EIP was not issued to them based on data from 2019 or 2020 return.

I checked with NSTP to get their take on the issue. Several preparers have inquired. They absolutely agree the IRS has created ambiguity with the question/answer in Topic B of the FAQ's.

For now, they are telling preparers to interpret "you" literally ( i.e the filing non-dependent) even though their parent received EIP as a result of their dependency in 1019 or 2020 and go ahead and claim the RRC if otherwise eligible.

Prudence however would suggest you alert the now 2021 non-dependent client that ambiguity does exists from IRS and the outcome of their return could be different than filed if the RRC is claimed. .