Apple is expected to debut the first version of its cellular modem next year in the iPhone SE 4, the iPhone 17 Air, and the base model iPad. The following year, it will debut a higher-end version of the chip with faster 5G connectivity for the iPhone 18 Pro.
As part of this transition, Apple is also investigating bringing cellular to the Mac as soon as 2026
That timeframe is less than ideal. I plan to buy a MacBook Air when it gets an M4 chip (early 2025?) but I so want cellular!