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.