Retirement tax questions

@dmertz Ah okay!  Thanks so much!   

 

So given that I completed a rollover (in 2020) from my old 401k custodian to my new 401k custodian, and forgot to input the 1099 from the old 401k custodian to my 2020 taxes, do I HAVE to file an amended tax return?   

 

What if I don't?   Will the IRS come get me?

 

Can I just not file an amended tax return and wait for the CP2000 to arrive and that's when I can send them my new 401k custodian's statement that says that I've indeed rolled it over?