I would guess that the problem that might occur, would be that the file transfer into the 2021 file could be improper if the unemployment change also changed a number of other items that need to be input properly into the 2021 tax returns. TTX may need to issue some support FAQs about that to the people affected as to whether they should start a 2020 Federal amendment anyhow (but not file it) so that those changes get logged into their 2020 tax file for xfer into 2021 taxes.
Perhaps @KatieH should include this on her list of discussion topics to cover for the Unemployment Q&A on September 9th....and maybe create an specific FAQ to cover this issue of transferring the IRS corrected tax data into taxpayers 2021 file:
https://ttlc.intuit.com/community/taxes/discussion/ask-the-experts-unemployment-q-a-september-9-2021...
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
