That being said, in the original context [0] it does sound a lot more like an option on the table. That original article presents it as the weakest of a list of things they're about to explore - but who knows, maybe the journalist has butchered what was said. It is an ambiguous idea without more context about how close it is to Mozilla trying to make life hard for ad-blockers.
[0] https://www.theverge.com/tech/845216/mozilla-ceo-anthony-enz...