Update 10 minutes later: It isn't working for me on theatlantic.com; I got the "free articles" drawers and then got blocked after they counted down to 0. So perhaps the answer to my question is "no".
I can whitelist third-party cookies on specific sites, but I don't think I can whitelist a single cookie across all sites. This seems unfortunate.
Update 30 minutes later: I tried disabling both cookie- and tracker-blocking in Firefox and still saw no sign of it working on theatlantic.com
Update 10 minutes later: It isn't working for me on theatlantic.com; I got the "free articles" drawers and then got blocked after they counted down to 0. So perhaps the answer to my question is "no".
I can whitelist third-party cookies on specific sites, but I don't think I can whitelist a single cookie across all sites. This seems unfortunate.
Update 30 minutes later: I tried disabling both cookie- and tracker-blocking in Firefox and still saw no sign of it working on theatlantic.com