https://www.cnet.com/news/samsung-may-ditch-the-iris-scanner-on-the-galaxy-s10/

Although Samsung introduced iris scanning only two years ago with the Galaxy Note 7, it looks like it may be retiring the feature for the Galaxy S10, according to Korean publication The Bell. 

The report claims that Samsung is already developing parts for the upcoming Galaxy S10, but has no plans to include an iris scanning module like in previous Galaxy phones.