You are misinformed. In the event of a penalty- the topic of this entire series of posts, Form 5329 is filed with your tax return. 5329 does include the RMD, and because of the TT bug it is the wrong RMD and wrong RMD distribution.
Besides that, the government gets a Form 5498 on all IRAs every year with the value of the RMD at the end of the previous year. Clearly they do know your age, and the IRA value, and therefore they can know your required RMD with just a tiny calculation. I think it would be a mistake to say they don't know the RMD amount unless you know what the IRS calculates while checking the return.
