Sure but COBOL can continue to run on S/360 in emulation. Alan Turing proved any computer can emulate any other computer. Emulation stories regularly appear on the front page of HN. If we can emulate game consoles and graphing calculators and personal computers from a couple of decades ago, why not taxes. I don't understand the issue of a critical skills shortage either. First of all, coding is coding. A real coder can adapt to any language. The required skills are the same to write code in any language. Only the specific syntax changes. And secondly if too few people know the specifics of COBOL and they need to learn it right now, open a COBOL boot camp. Seriously. COBOL can be maintained as long as people just care enough to do it.
Way before the code was the contract with Ethereum, the IMF and BMF are the tax law.
If the printed regs say one thing and the masterfiles do another, the masterfile was always right.
Laughable that anyone thinks they can replace 60 years of logic.