As I mentioned in the article, I specifically confirmed this scenario with immigration. There no longer is a specialist in humanities visa, but rather it got merged into a status called Engineer/Specialist in Humanities/International Services. While they do care about your education background when applying for the initial visa, it doesn’t matter after that, so you are allowed to do whatever work is permitted by it (so you can do a programming related job). For renewing it, it doesn’t matter if your degree doesn’t match. This is based on talking to immigration’s consulting hotline, which is conservative about this kind of stuff.
If you’re still confirmed, you could try contacting them yourself. Though you should be aware that the phone lines are often quite busy, so it may take some time to get through.