I do have the Facebook trackers disabled in Ghostery but I wonder if that’s enough

You're being additionally tracked in the reverse by a third party affiliate on the knowledge of you being a person who blocks Facebook, if that makes any sense.

Adblock detectors that function in the same vein as "FuckAdblock" look at if the client blocked a Facebook pixel.

Seems like the fingerprinting that can be done in this case is much less -- the affiliate would just get "ip / website / using-adblock" instead of "ip / website / FB profile ID" right?

Or are the websites providing identifying information like email? (I've never heard of this but I'm not well-versed here).

It's more like the combination of ip / website / using-adblock / screen resoluction / installed fonts / installed plugins and their versions / hash-this / hash-that are individually non-identifying by themselves, but a combination of them can be used to uniquely identify an individual. [1]

But who, exactly, is the individual? Well, that comes later. Maybe your blocker fails to block something that is gathering that data plus your identity. Now, all of that activity (that was previously not tied to an individual) can now be safely linked to you, the individual.

1: https://panopticlick.eff.org/

Very good point, those fingerprinting techniques were what I was missing.

Also, thanks for sharing that EFF link, I really like the breakdown of how much entropy they can get from each fingerprint dimension.

I do not doubt this, but do you have more information/sources?