Seems like a distinction without a difference:

"Glyphosate is a broad-spectrum systemic herbicide and crop desiccant. It is used to kill weeds, especially annual broadleaf weeds and grasses that compete with crops. Its herbicidal effectiveness was discovered by Monsanto chemist John E. Franz in 1970. Monsanto brought it to market for agricultural use in 1974 under the trade name Roundup."

https://en.wikipedia.org/wiki/Glyphosate

It’s a distinction without a difference if you’re trying to reuse the tobacco playbook and you need people to be confused long enough for your bonus checks to clear.

I think what they are meaning is that the chemical blend with glyphosate causes cancer even if pure glyphosate doesn't. I.e. an inactive ingredient or an interaction with an inactive ingredient is what causes the cancer.