… and the IARC monograph on Roundup, in turn, has been dismissed universally by experts as both flawed and misleading. Amongst other things, they arbitrarily excluded high-quality studies that showed no evidence of carcinogenicity, and included at least one study claiming to show an effect but in reality failed to do so (it didn’t show dose dependence, which means the result is not statistically robust but rather a random fluke). The scientific consensus is completely on Monsanto’s side in this debate. Pretending otherwise is simply dishonest, there’s no other word for it.

If that is the case then it shouldn't be a problem to ask IARC to make a new monograph. That this doesn't happen tells me that the case isn't as simple here as you say.