I think content-esque updates tend to be the the sweet spot on resources/ROI for games such as Age of Empires II expansions. I can imagine codebases for older

I think content-esque updates tend to be the the sweet spot on resources/ROI for games such as Age of Empires II expansions. I can imagine codebases for older games are likely written in an older dialect of C++ (and probably in a very C style at the time, to boot) and likely haven’t had any ongoing maintenance or technical debt addressed. Most of the income from the product came from one win32 binary (plus perhaps an update) that shipped on CD years ago. The engineering/QA cost of writing or maintaining new features is going to be high, so I can imagine a publisher is going to look at the returns of an expansion to an old game and see that a conservative release is the most economic bet to make.