I don't think freebitcoin has any special lists of users to distribute WoF spins. And those cases when some users get spins even after selling FUN tokens seem to be just another bug.
Frankly speaking, it isn't clear why the freebitcoin team has had problems with the distribution of WoF spins since last year. From a technical point of view, the distribution of spins to premium users shouldn't be a difficult task.
I can't talk about technical things, but it seems you are right that it is another bug they have. I heard before that people did not receive their WOF spins, but this time I am hearing that some people got some free WOF spins even after they sold their FUN tokens. Initially, I thought it was of glitch or maybe they are rewarding people because of the previous issues with WOF spins.
But seems like not only a few people received WOF spins after selling their Fun token, but not everyone. It confirms that it is another bug on their website and it's been around for a year which they did not fixed yet.
I don't think so, perhaps the premium wof distribution system were paused, and now they're gonna resume it, and because of that , it's paying for those who didn't get it until the day they sold their tokens.