Taking a picture instantly after would probably create a different hash value. The thing about hashing is that even if one bit is different between source images, the resulting hashes would look entirely different.
I suppose I could conceive of a proprietary hash algorithm that would allow for fuzzy matching of iris photos, but as you said, eyes taken years apart in different conditions wouldn't match the original hash. Or falsely match similar looking eyes. It's not like this system allows them to get high resolution perfectly lit iris photos, after all.
The whole thing sounds dubious, and I suspect AI is mentioned solely to secure investor funding, much like how several years back everything mentioned Blockchain.
I thought about this before, and mostly agree. My mom knows nothing about computers and could probably use Ubuntu if I stick it on a machine and gave it to her. The thing preventing me from doing it is that when things go wrong in Linux, it often requires extensive terminal usage to fix. And my mother can often find new and creative ways to break a computer. If something went wrong with it, I would have to fix it. There is literally no one else she knows who would even know where to start. At least if she's on windows, she can find someone to help her.