[ruh-roh]

I am genuinely interested in this, please excuse my naivety.

My expectation would be that new Product work would, at some high-ish level, be sanctioned by company leadership. Or you wouldn't be spending weeks/months/years on it. Ideally Marketing would be involved in that leadership decision, and this is where they could raise that kind of concern. But even if they are not, Marketing's "boss" (CEO) could/should tell them they need to market it or go pound sand.