https://www.theverge.com/2018/7/31/17633906/apple-iphone-dual-sim-ios-12-beta-references

Rumors of a dual-SIM iPhone first emerged earlier this year, and now Apple’s own iOS 12 is backing up the reports. A new “iPhone X Plus” is rumored to include a 6.5-inch OLED display and dual-SIM support in certain regions. 9to5Mac reports that iOS 12 developer beta 5, released yesterday, includes references to dual-SIM support. The operating system even mentions a second physical SIM tray, meaning an iPhone with dual-SIM support might not be restricted to a single SIM tray and eSIM support.

Dual-SIM support for an iPhone would be