Mary Smith's husband died decades ago.  At least 15 years ago she remarried, John Jones.  They have since been filing (non-electronically) as John and Mary Jones.  Mary changed her name with Social Security.  They just got a notice about their 2022 return, addressed to John Jones and Mary Smith.  My conclusion is that IRS doesn't keypunch the names, but only the SSN's.  Then the name pops up on the screen and no one looks too closely to see if it has changed.   Anyone else come across this situation?  Sort of annoying.  

But that's not the problem you have.  I am fairly sure that IRS uses Post Office software that corrects the ZIP Code when it is not correct.  Same thing that my Stamps.com software does when I create a mailing label.  And if you only enter a 5-digit ZIP, they'll add the last 4.  So go ahead and change it, if you're sure it's correct, but if you don't, they will anyway.