That may be possible if they are zombified.
Given the discussion was about the central three characters, who are living, and the photos shown were for those same characters and not the zombies, I wouldn't want to be the one defending against a celebrity with deep enough pockets to sue me because I lifted their likeness for a purely commercial pursuit without seeking permission or offering compensation.
That's especially true if you've got a camera and a family and they are willing volunteers.
There would be tons of insurance available and a duty to defend. I wouldn't get too worked up about defending a slap suit ... it's been a long, long time since I've looked at that issue, but my recollection is that Jerry's statement of the common law rule is correct. Average people get attacked by armies of attorneys for multinational corporations and do just fine with often very inexperienced and poorly funded attorneys. But I'd have to think about the issue some more to have a firm opinion on it.
You are aware that several states have deemed through statute and case law precedent ( both of which trump common law) that these rights, sometimes called Publicity Rights, are a property right and can be enforced by both the person being infringed upon and their families up to 75 years past their death, right?
The states that didn't make it a property right seem to fall on it being a tort, which dies with the person whose likeness is being used. It's an offshoot of privacy rights that have gained in strength recently across the country.
A lot of it will be determined on what state the person who's likeness is being used resides in and makes their permanent residence currently or at the time of death. This was a key component in the case of Marylin Monroe's likeness rights.
That issue, states doing whatever they want on an individual basis, is why there is confusion in some circles.
Tony got C & D letters from the both zombies in this piece.