Retirement tax questions

I have another question.

 

I chatted with the IRS folks on their helpline and told them about the two options offered in this thread:

- Report the 1099-R now which I'll receive next year, OR

- Wait to actually receive it next year and then file a 2020 amended tax and mention that 1099-R in it

 

When I told them this, they mentioned that if I go with the second option, I don't have to amend the 2020 tax return, and can instead just file it with the normal 2021 tax return. I called them twice and two different agents said this same thing to me. I assume since the 1099-R will be coded correctly, the IRS can maybe figure out themselves that it's for withdrawing a 2020 excess contribution that was withdrawn in 2021. I also talked with the brokerage where I have my Roth IRA, and they also suggested the same thing.

 

So are you sure I would need to do an 2020 amendment if I wait to actually receive the 1099-R form next year ?