A new article in Bloomberg substantiates earlier claims that Apple will not adopt 5G in its next-generation iPhones. In fact, the outlet's sources have suggested that this may not happen until after 2020. The company's current enmity to Qualcomm may be a factor in the apparent delay.
https://www.notebookcheck.net/New-report-casts-further-doubt-on-prospect-of-5G-iPhones-in-2019.373911.0.html