It likely is a bit overblown. Moreover, it's a very good point that it's a bad system when it only delineates what confidence there is that a compound can cause cancer, and not how strong the effect is. Lots of things are technically carcinogenic, but with the effect being so weak it's negligible. Technically we already know formaldehyde is a metabolite of aspartame, and that formaldehyde is carcinogenic, but the amounts involved mean it's going to be a very minor contributor to cancer risk.