I don't think whether a player appeared in minicamp or not matters or in anyway is directly related to PUP. It basically has to do with practice at camp and whether they are given clearance to participate in training camp or not.
There are many as mentioned who may NOT be ready at the start of camp,
and may be PUPed if they are no ready through camp, but if a player somehow injures himself between the minicamp and traiing camp he's certainly eligible for PUP.