Nothing, except the perception of what was said and what was actually said. (The same happend to Bells inequality actually)

“ (…) you can just mimic the behavior of complex numbers using pairs of real numbers (and appropriately tweaked definitions of operations). (…) What Renou et al are actually claiming is that if you start with quantum mechanics, and then remove all operations and states involving non-real numbers, and then try to emulate what was lost using what remains, you will fail in an experimentally detectable way”

Meaning it’s actually totally possible to only use reals to encode the complex Numbers, but not to also remove all operators which do the same things as the complex numbers would.