The effort wanted to replace all uses of Pi (including the ones in math formulas) and not just their use in (floating-point) computer programs where we implement approximations of those formulas.
But just because there was {a lot of work to replace all uses of pi with tau} doesn't mean there wasn't {a lot of work to replace all approximate uses of pi with approximate uses of tau in computer programs}.
Nothing in the rest of the article deals with pi or tau as transcendental numbers, only about a bit patterns and (implicitly) floats or doubles.
If your focus is IEEE 754 apples, then perhaps other sorts of fruit aren't so important?