it gets sticky when you sell your product of work based on a public domain image. maybe the original image that is available in the public domain is dirty, scratches, faded, or any other thing that happens with old images. if they paid to have it restored and are selling the restored image, then that image is not part of the public domain. it's a big bit of spin on this being a possible misunderstanding of what they are doing.
however, with all of the other stories about the original photographer getting served notices of infringement when they have their image on their own site or socials and similar type of just unchecked automation, then yeah, it's hard to be able to give any benefit of the doubt
then something else can be done to it that does grant them copyright on the work product. similar to modifying the mouse to extend/grant new copyrights
however, with all of the other stories about the original photographer getting served notices of infringement when they have their image on their own site or socials and similar type of just unchecked automation, then yeah, it's hard to be able to give any benefit of the doubt