That could already be the case. The initial release is from 1990, so the codebase is at least 35 years old.

I don't have a good guess for the average age of software developers at Microsoft, but claude.ai guesses the average "around 33-38 years" and the median "around 35-36 years old".

"but claude.ai guesses"

To my ears this is the equivalent of "some guy down the pub said", but maybe I am a luddite.

You're not a luddite, they disclosed it because you're _supposed_ to take it with a grain of salt

Office was released in 1990, but Excel in 1985 and Word in 1983.

I'm told from MS friends that there are still files with the intact 1987 changelog in Word; as well as workarounds for dot matrix printers that were released 40+ years ago.

Also, the Office codebase is significantly larger than Windows (and has been for a while), that was surprising to me.